CrimsonEDR is an open-source project engineered to identify specific malware patterns, offering a tool for honing skills in circumventing Endpoint Detection and Response (EDR). By leveraging diverse detection methods, it empowers users to deepen their understanding of security evasion tactics.
Detection | Description |
---|---|
Direct Syscall | Detects the usage of direct system calls, often employed by malware to bypass traditional API hooks. |
NTDLL Unhooking | Identifies attempts to unhook functions within the NTDLL library, a common evasion technique. |
AMSI Patch | Detects modifications to the Anti-Malware Scan Interface (AMSI) through byte-level analysis. |
ETW Patch | Detects byte-level alterations to Event Tracing for Windows (ETW), commonly manipulated by malware to evade detection. |
PE Stomping | Identifies instances of PE (Portable Executable) stomping. |
Reflective PE Loading | Detects the reflective loading of PE files, a technique employed by malware to avoid static analysis. |
Unbacked Thread Origin | Identifies threads originating from unbacked memory regions, often indicative of malicious activity. |
Unbacked Thread Start Address | Detects threads with start addresses pointing to unbacked memory, a potential sign of code injection. |
API hooking | Places a hook on the NtWriteVirtualMemory function to monitor memory modifications. |
Custom Pattern Search | Allows users to search for specific patterns provided in a JSON file, facilitating the identification of known malware signatures. |
To get started with CrimsonEDR, follow these steps:
bash sudo apt-get install gcc-mingw-w64-x86-64
bash git clone https://github.com/Helixo32/CrimsonEDR
bash cd CrimsonEDR; chmod +x compile.sh; ./compile.sh
Windows Defender and other antivirus programs may flag the DLL as malicious due to its content containing bytes used to verify if the AMSI has been patched. Please ensure to whitelist the DLL or disable your antivirus temporarily when using CrimsonEDR to avoid any interruptions.
To use CrimsonEDR, follow these steps:
ioc.json
file is placed in the current directory from which the executable being monitored is launched. For example, if you launch your executable to monitor from C:\Users\admin\
, the DLL will look for ioc.json
in C:\Users\admin\ioc.json
. Currently, ioc.json
contains patterns related to msfvenom
. You can easily add your own in the following format:{
"IOC": [
["0x03", "0x4c", "0x24", "0x08", "0x45", "0x39", "0xd1", "0x75"],
["0xf1", "0x4c", "0x03", "0x4c", "0x24", "0x08", "0x45", "0x39"],
["0x58", "0x44", "0x8b", "0x40", "0x24", "0x49", "0x01", "0xd0"],
["0x66", "0x41", "0x8b", "0x0c", "0x48", "0x44", "0x8b", "0x40"],
["0x8b", "0x0c", "0x48", "0x44", "0x8b", "0x40", "0x1c", "0x49"],
["0x01", "0xc1", "0x38", "0xe0", "0x75", "0xf1", "0x4c", "0x03"],
["0x24", "0x49", "0x01", "0xd0", "0x66", "0x41", "0x8b", "0x0c"],
["0xe8", "0xcc", "0x00", "0x00", "0x00", "0x41", "0x51", "0x41"]
]
}
Execute CrimsonEDRPanel.exe
with the following arguments:
-d <path_to_dll>
: Specifies the path to the CrimsonEDR.dll
file.
-p <process_id>
: Specifies the Process ID (PID) of the target process where you want to inject the DLL.
For example:
.\CrimsonEDRPanel.exe -d C:\Temp\CrimsonEDR.dll -p 1234
Here are some useful resources that helped in the development of this project:
For questions, feedback, or support, please reach out to me via:
There are indications that U.S. healthcare giant Change Healthcare has made a $22 million extortion payment to the infamous BlackCat ransomware group (a.k.a. “ALPHV“) as the company struggles to bring services back online amid a cyberattack that has disrupted prescription drug services nationwide for weeks. However, the cybercriminal who claims to have given BlackCat access to Change’s network says the crime gang cheated them out of their share of the ransom, and that they still have the sensitive data Change reportedly paid the group to destroy. Meanwhile, the affiliate’s disclosure appears to have prompted BlackCat to cease operations entirely.
Image: Varonis.
In the third week of February, a cyber intrusion at Change Healthcare began shutting down important healthcare services as company systems were taken offline. It soon emerged that BlackCat was behind the attack, which has disrupted the delivery of prescription drugs for hospitals and pharmacies nationwide for nearly two weeks.
On March 1, a cryptocurrency address that security researchers had already mapped to BlackCat received a single transaction worth approximately $22 million. On March 3, a BlackCat affiliate posted a complaint to the exclusive Russian-language ransomware forum Ramp saying that Change Healthcare had paid a $22 million ransom for a decryption key, and to prevent four terabytes of stolen data from being published online.
The affiliate claimed BlackCat/ALPHV took the $22 million payment but never paid him his percentage of the ransom. BlackCat is known as a “ransomware-as-service” collective, meaning they rely on freelancers or affiliates to infect new networks with their ransomware. And those affiliates in turn earn commissions ranging from 60 to 90 percent of any ransom amount paid.
“But after receiving the payment ALPHV team decide to suspend our account and keep lying and delaying when we contacted ALPHV admin,” the affiliate “Notchy” wrote. “Sadly for Change Healthcare, their data [is] still with us.”
Change Healthcare has neither confirmed nor denied paying, and has responded to multiple media outlets with a similar non-denial statement — that the company is focused on its investigation and on restoring services.
Assuming Change Healthcare did pay to keep their data from being published, that strategy seems to have gone awry: Notchy said the list of affected Change Healthcare partners they’d stolen sensitive data from included Medicare and a host of other major insurance and pharmacy networks.
On the bright side, Notchy’s complaint seems to have been the final nail in the coffin for the BlackCat ransomware group, which was infiltrated by the FBI and foreign law enforcement partners in late December 2023. As part of that action, the government seized the BlackCat website and released a decryption tool to help victims recover their systems.
BlackCat responded by re-forming, and increasing affiliate commissions to as much as 90 percent. The ransomware group also declared it was formally removing any restrictions or discouragement against targeting hospitals and healthcare providers.
However, instead of responding that they would compensate and placate Notchy, a representative for BlackCat said today the group was shutting down and that it had already found a buyer for its ransomware source code.
The seizure notice now displayed on the BlackCat darknet website.
“There’s no sense in making excuses,” wrote the RAMP member “Ransom.” “Yes, we knew about the problem, and we were trying to solve it. We told the affiliate to wait. We could send you our private chat logs where we are shocked by everything that’s happening and are trying to solve the issue with the transactions by using a higher fee, but there’s no sense in doing that because we decided to fully close the project. We can officially state that we got screwed by the feds.”
BlackCat’s website now features a seizure notice from the FBI, but several researchers noted that this image seems to have been merely cut and pasted from the notice the FBI left in its December raid of BlackCat’s network. The FBI has not responded to requests for comment.
Fabian Wosar, head of ransomware research at the security firm Emsisoft, said it appears BlackCat leaders are trying to pull an “exit scam” on affiliates by withholding many ransomware payment commissions at once and shutting down the service.
“ALPHV/BlackCat did not get seized,” Wosar wrote on Twitter/X today. “They are exit scamming their affiliates. It is blatantly obvious when you check the source code of their new takedown notice.”
Dmitry Smilyanets, a researcher for the security firm Recorded Future, said BlackCat’s exit scam was especially dangerous because the affiliate still has all the stolen data, and could still demand additional payment or leak the information on his own.
“The affiliates still have this data, and they’re mad they didn’t receive this money, Smilyanets told Wired.com. “It’s a good lesson for everyone. You cannot trust criminals; their word is worth nothing.”
BlackCat’s apparent demise comes closely on the heels of the implosion of another major ransomware group — LockBit, a ransomware gang estimated to have extorted over $120 million in payments from more than 2,000 victims worldwide. On Feb. 20, LockBit’s website was seized by the FBI and the U.K.’s National Crime Agency (NCA) following a months-long infiltration of the group.
LockBit also tried to restore its reputation on the cybercrime forums by resurrecting itself at a new darknet website, and by threatening to release data from a number of major companies that were hacked by the group in the weeks and days prior to the FBI takedown.
But LockBit appears to have since lost any credibility the group may have once had. After a much-promoted attack on the government of Fulton County, Ga., for example, LockBit threatened to release Fulton County’s data unless paid a ransom by Feb. 29. But when Feb. 29 rolled around, LockBit simply deleted the entry for Fulton County from its site, along with those of several financial organizations that had previously been extorted by the group.
Fulton County held a press conference to say that it had not paid a ransom to LockBit, nor had anyone done so on their behalf, and that they were just as mystified as everyone else as to why LockBit never followed through on its threat to publish the county’s data. Experts told KrebsOnSecurity LockBit likely balked because it was bluffing, and that the FBI likely relieved them of that data in their raid.
Smilyanets’ comments are driven home in revelations first published last month by Recorded Future, which quoted an NCA official as saying LockBit never deleted the data after being paid a ransom, even though that is the only reason many of its victims paid.
“If we do not give you decrypters, or we do not delete your data after payment, then nobody will pay us in the future,” LockBit’s extortion notes typically read.
Hopefully, more companies are starting to get the memo that paying cybercrooks to delete stolen data is a losing proposition all around.
The ransomware group LockBit told officials with Fulton County, Ga. they could expect to see their internal documents published online this morning unless the county paid a ransom demand. LockBit removed Fulton County’s listing from its victim shaming website this morning, claiming the county had paid. But county officials said they did not pay, nor did anyone make payment on their behalf. Security experts say LockBit was likely bluffing and probably lost most of the data when the gang’s servers were seized this month by U.S. and U.K. law enforcement.
The LockBit website included a countdown timer until the promised release of data stolen from Fulton County, Ga. LockBit would later move this deadline up to Feb. 29, 2024.
LockBit listed Fulton County as a victim on Feb. 13, saying that unless it was paid a ransom the group would publish files stolen in a breach at the county last month. That attack disrupted county phones, Internet access and even their court system. LockBit leaked a small number of the county’s files as a teaser, which appeared to include sensitive and sealed court records in current and past criminal trials.
On Feb. 16, Fulton County’s entry — along with a countdown timer until the data would be published — was removed from the LockBit website without explanation. The leader of LockBit told KrebsOnSecurity this was because Fulton County officials had engaged in last-minute negotiations with the group.
But on Feb. 19, investigators with the FBI and the U.K.’s National Crime Agency (NCA) took over LockBit’s online infrastructure, replacing the group’s homepage with a seizure notice and links to LockBit ransomware decryption tools.
In a press briefing on Feb. 20, Fulton County Commission Chairman Robb Pitts told reporters the county did not pay a ransom demand, noting that the board “could not in good conscience use Fulton County taxpayer funds to make a payment.”
Three days later, LockBit reemerged with new domains on the dark web, and with Fulton County listed among a half-dozen other victims whose data was about to be leaked if they refused to pay. As it does with all victims, LockBit assigned Fulton County a countdown timer, saying officials had until late in the evening on March 1 until their data was published.
LockBit revised its deadline for Fulton County to Feb. 29.
LockBit soon moved up the deadline to the morning of Feb. 29. As Fulton County’s LockBit timer was counting down to zero this morning, its listing disappeared from LockBit’s site. LockBit’s leader and spokesperson, who goes by the handle “LockBitSupp,” told KrebsOnSecurity today that Fulton County’s data disappeared from their site because county officials paid a ransom.
“Fulton paid,” LockBitSupp said. When asked for evidence of payment, LockBitSupp claimed. “The proof is that we deleted their data and did not publish it.”
But at a press conference today, Fulton County Chairman Robb Pitts said the county does not know why its data was removed from LockBit’s site.
“As I stand here at 4:08 p.m., we are not aware of any data being released today so far,” Pitts said. “That does not mean the threat is over. They could release whatever data they have at any time. We have no control over that. We have not paid any ransom. Nor has any ransom been paid on our behalf.”
Brett Callow, a threat analyst with the security firm Emsisoft, said LockBit likely lost all of the victim data it stole before the FBI/NCA seizure, and that it has been trying madly since then to save face within the cybercrime community.
“I think it was a case of them trying to convince their affiliates that they were still in good shape,” Callow said of LockBit’s recent activities. “I strongly suspect this will be the end of the LockBit brand.”
Others have come to a similar conclusion. The security firm RedSense posted an analysis to Twitter/X that after the takedown, LockBit published several “new” victim profiles for companies that it had listed weeks earlier on its victim shaming site. Those victim firms — a healthcare provider and major securities lending platform — also were unceremoniously removed from LockBit’s new shaming website, despite LockBit claiming their data would be leaked.
“We are 99% sure the rest of their ‘new victims’ are also fake claims (old data for new breaches),” RedSense posted. “So the best thing for them to do would be to delete all other entries from their blog and stop defrauding honest people.”
Callow said there certainly have been plenty of cases in the past where ransomware gangs exaggerated their plunder from a victim organization. But this time feels different, he said.
“It is a bit unusual,” Callow said. “This is about trying to still affiliates’ nerves, and saying, ‘All is well, we weren’t as badly compromised as law enforcement suggested.’ But I think you’d have to be a fool to work with an organization that has been so thoroughly hacked as LockBit has.”
py-amsi is a library that scans strings or files for malware using the Windows Antimalware Scan Interface (AMSI) API. AMSI is an interface native to Windows that allows applications to ask the antivirus installed on the system to analyse a file/string. AMSI is not tied to Windows Defender. Antivirus providers implement the AMSI interface to receive calls from applications. This library takes advantage of the API to make antivirus scans in python. Read more about the Windows AMSI API here.
Via pip
pip install pyamsi
Clone repository
git clone https://github.com/Tomiwa-Ot/py-amsi.git
cd py-amsi/
python setup.py install
from pyamsi import Amsi
# Scan a file
Amsi.scan_file(file_path, debug=True) # debug is optional and False by default
# Scan string
Amsi.scan_string(string, string_name, debug=False) # debug is optional and False by default
# Both functions return a dictionary of the format
# {
# 'Sample Size' : 68, // The string/file size in bytes
# 'Risk Level' : 0, // The risk level as suggested by the antivirus
# 'Message' : 'File is clean' // Response message
# }
Risk Level | Meaning |
---|---|
0 | AMSI_RESULT_CLEAN (File is clean) |
1 | AMSI_RESULT_NOT_DETECTED (No threat detected) |
16384 | AMSI_RESULT_BLOCKED_BY_ADMIN_START (Threat is blocked by the administrator) |
20479 | AMSI_RESULT_BLOCKED_BY_ADMIN_END (Threat is blocked by the administrator) |
32768 | AMSI_RESULT_DETECTED (File is considered malware) |
https://tomiwa-ot.github.io/py-amsi/index.html
MSI Dump - a tool that analyzes malicious MSI installation packages, extracts files, streams, binary data and incorporates YARA scanner.
On Macro-enabled Office documents we can quickly use oletools mraptor to determine whether document is malicious. If we want to dissect it further, we could bring in oletools olevba or oledump.
To dissect malicious MSI files, so far we had only one, but reliable and trustworthy lessmsi. However, lessmsi
doesn't implement features I was looking for:
Hence this is where msidump
comes into play.
This tool helps in quick triages as well as detailed examinations of malicious MSIs corpora. It lets us:
file
/MIME type deduction to determine inner data typeIt was created as a companion tool to the blog post I released here:
WindowsInstaller.Installer
interfaces, currently it is not possible to support native Linux platforms. Maybe wine python msidump.py
could help, but haven't tried that yet.cmd> python msidump.py evil.msi -y rules.yara
Here we can see that input MSI is injected with suspicious VBScript and contains numerous executables in it.
We see from the triage table that it was present in Binary
table. Lets get him:
python msidump.py putty-backdoored.msi -l binary -i UBXtHArj
We can specify which to record dump either by its name/ID or its index number (here that would be 7).
Lets have a look at another example. This time there is executable stored in Binary
table that will be executed during installation:
To extract that file we're gonna go with
python msidump.py evil2.msi -x binary -i lmskBju -O extracted
Where
-x binary
tells to extract contents of Binary
table-i lmskBju
specifies which record exactly to extract-O extracted
sets output directoryFor the best output experience, run the tool on a maximized console window or redirect output to file:
python msidump.py [...] -o analysis.log
PS D:\> python .\msidump.py --help
options:
-h, --help show this help message and exit
Required arguments:
infile Input MSI file (or directory) for analysis.
Options:
-q, --quiet Surpress banner and unnecessary information. In triage mode, will display only verdict.
-v, --verbose Verbose mode.
-d, --debug Debug mode.
-N, --nocolor Dont use colors in text output.
-n PRINT_LEN, --print-len PRINT_LEN
When previewing data - how many bytes to include in preview/hexdump. Default: 128
-f {text,json,csv}, --format {text,json,csv}
Output format: text, json, csv. Default: text
-o path, --outfile path
Redirect program output to this file.
-m, --mime When sniffing inner data type, report MIME types
Analysis Modes:
-l what, --list what List specific table contents. See help message to learn what can be listed.
-x what, --extract what
Extract data from MSI. For what can be extracted, refer to help message.
Analysis Specific options:
-i number|name, --record number|name
Can be a number or name. In --list mode, specifies which record to dump/display entirely. In --extract mode dumps only this particular record to --outdir
-O path, --outdir path
When --extract mode is used, specifies output location where to extract data.
-y path, --yara path Path to YARA rule/directory with rules. YARA will be matched against Binary data, streams and inner files
------------------------------------------------------
- What can be listed:
--list CustomAction - Specific table
--lis t Registry,File - List multiple tables
--list stats - Print MSI database statistics
--list all - All tables and their contents
--list olestream - Prints all OLE streams & storages.
To display CABs embedded in MSI try: --list _Streams
--list cabs - Lists embedded CAB files
--list binary - Lists binary data embedded in MSI for its own purposes.
That typically includes EXEs, DLLs, VBS/JS scripts, etc
- What can be extracted:
--extract all - Extracts Binary data, all files from CABs, scripts from CustomActions
--extract binary - Extracts Binary data
--extract files - Extracts files
--extract cabs - Extracts cabinets
--extract scripts - Extrac ts scripts
------------------------------------------------------
CustomAction Type
s based on assessing their numbers, which is prone to being evaded. Apparently when naming my tool, I didn't think on checking whether it was already taken. There is another tool named msidump
being part of msitools GNU package:
This and other projects are outcome of sleepless nights and plenty of hard work. If you like what I do and appreciate that I always give back to the community, Consider buying me a coffee (or better a beer) just to say thank you!
Mariusz Banach / mgeeky, (@mariuszbit)
<mb [at] binary-offensive.com>
Ransomware groups are constantly devising new methods for infecting victims and convincing them to pay up, but a couple of strategies tested recently seem especially devious. The first centers on targeting healthcare organizations that offer consultations over the Internet and sending them booby-trapped medical records for the “patient.” The other involves carefully editing email inboxes of public company executives to make it appear that some were involved in insider trading.
Alex Holden is founder of Hold Security, a Milwaukee-based cybersecurity firm. Holden’s team gained visibility into discussions among members of two different ransom groups: CLOP (a.k.a. “Cl0p” a.k.a. “TA505“), and a newer ransom group known as Venus.
Last month, the U.S. Department of Health and Human Services (HHS) warned that Venus ransomware attacks were targeting a number of U.S. healthcare organizations. First spotted in mid-August 2022, Venus is known for hacking into victims’ publicly-exposed Remote Desktop services to encrypt Windows devices.
Holden said the internal discussions among the Venus group members indicate this gang has no problem gaining access to victim organizations.
“The Venus group has problems getting paid,” Holden said. “They are targeting a lot of U.S. companies, but nobody wants to pay them.”
Which might explain why their latest scheme centers on trying to frame executives at public companies for insider trading charges. Venus indicated it recently had success with a method that involves carefully editing one or more email inbox files at a victim firm — to insert messages discussing plans to trade large volumes of the company’s stock based on non-public information.
“We imitate correspondence of the [CEO] with a certain insider who shares financial reports of his companies through which your victim allegedly trades in the stock market, which naturally is a criminal offense and — according to US federal laws [includes the possibility of up to] 20 years in prison,” one Venus member wrote to an underling.
“You need to create this file and inject into the machine(s) like this so that metadata would say that they were created on his computer,” they continued. “One of my clients did it, I don’t know how. In addition to pst, you need to decompose several files into different places, so that metadata says the files are native from a certain date and time rather than created yesterday on an unknown machine.”
Holden said it’s not easy to plant emails into an inbox, but it can be done with Microsoft Outlook .pst files, which the attackers may also have access to if they’d already compromised a victim network.
“It’s not going to be forensically solid, but that’s not what they care about,” he said. “It still has the potential to be a huge scandal — at least for a while — when a victim is being threatened with the publication or release of these records.”
The Venus ransom group’s extortion note. Image: Tripwire.com
Holden said the CLOP ransomware gang has a different problem of late: Not enough victims. The intercepted CLOP communication seen by KrebsOnSecurity shows the group bragged about twice having success infiltrating new victims in the healthcare industry by sending them infected files disguised as ultrasound images or other medical documents for a patient seeking a remote consultation.
The CLOP members said one tried-and-true method of infecting healthcare providers involved gathering healthcare insurance and payment data to use in submitting requests for a remote consultation on a patient who has cirrhosis of the liver.
“Basically, they’re counting on doctors or nurses reviewing the patient’s chart and scans just before the appointment,” Holden said. “They initially discussed going in with cardiovascular issues, but decided cirrhosis or fibrosis of the liver would be more likely to be diagnosable remotely from existing test results and scans.”
While CLOP as a money making collective is a fairly young organization, security experts say CLOP members hail from a group of Threat Actors (TA) known as “TA505,” which MITRE’s ATT&CK database says is a financially motivated cybercrime group that has been active since at least 2014. “This group is known for frequently changing malware and driving global trends in criminal malware distribution,” MITRE assessed.
In April, 2021, KrebsOnSecurity detailed how CLOP helped pioneer another innovation aimed at pushing more victims into paying an extortion demand: Emailing the ransomware victim’s customers and partners directly and warning that their data would be leaked to the dark web unless they can convince the victim firm to pay up.
Security firm Tripwire points out that the HHS advisory on Venus says multiple threat actor groups are likely distributing the Venus ransomware. Tripwire’s tips for all organizations on avoiding ransomware attacks include:
While the above tips are important and useful, one critical area of ransomware preparedness overlooked by too many organizations is the need to develop — and then periodically rehearse — a plan for how everyone in the organization should respond in the event of a ransomware or data ransom incident. Drilling this breach response plan is key because it helps expose weaknesses in those plans that could be exploited by the intruders.
As noted in last year’s story Don’t Wanna Pay Ransom Gangs? Test Your Backups, experts say the biggest reason ransomware targets and/or their insurance providers still pay when they already have reliable backups of their systems and data is that nobody at the victim organization bothered to test in advance how long this data restoration process might take.
“Suddenly the victim notices they have a couple of petabytes of data to restore over the Internet, and they realize that even with their fast connections it’s going to take three months to download all these backup files,” said Fabian Wosar, chief technology officer at Emsisoft. “A lot of IT teams never actually make even a back-of-the-napkin calculation of how long it would take them to restore from a data rate perspective.”
It’s hard to imagine a world without cellphones. Whether it be a smartphone or a flip phone, these devices have truly shaped the late 20th century and will continue to do so for the foreseeable future. But while users have become accustomed to having almost everything they could ever want at fingertips length, cybercriminals were busy setting up shop. To trick unsuspecting users, cybercriminals have set up crafty mobile threats – some that users may not even be fully aware of. These sneaky cyberthreats include SMSishing, fake networks, malicious apps, and grayware, which have all grown in sophistication over time. This means users need to be equipped with the know-how to navigate the choppy waters that come with these smartphone-related cyberthreats. Let’s get started.
If you use email, then you are probably familiar with what phishing is. And while phishing is commonly executed through email and malicious links, there is a form of phishing that specifically targets mobile devices called SMSishing. This growing threat allows cybercriminals to utilize messaging apps to send unsuspecting users a SMSishing message. These messages serve one purpose – to obtain personal information, such as logins and financial information. With that information, cybercriminals could impersonate the user to access banking records or steal their identity.
While this threat was once a rarity, its the rise in popularity is two-fold. The first aspect is that users have been educated to distrust email messages and the second is the rise in mobile phone usage throughout the world. Although this threat shows no sign of slowing down, there are ways to avoid a cybercriminal’s SMSishing hooks. Get started with these tips:
Public and free Wi-Fi is practically everywhere nowadays, with some destinations even having city-wide Wi-Fi set up. But that Wi-Fi users are connecting their mobile device to may not be the most secure, given cybercriminals can exploit weaknesses in these networks to intercept messages, login credentials, or other personal information. Beyond exploiting weaknesses, some cybercriminals take it a step further and create fake networks with generic names that trick unsuspecting users into connecting their devices. These networks are called “evil-twin” networks. For help in spotting these imposters, there are few tricks the savvy user can deploy to prevent an evil twin network from wreaking havoc on their mobile device:
Fake apps have become a rampant problem for Android and iPhone users alike. This is mainly in part due to malicious apps hiding in plain sight on legitimate sources, such as the Google Play Store and Apple’s App Store. After users download a faulty app, cybercriminals deploy malware that operates in the background of mobile devices which makes it difficult for users to realize anything is wrong. And while users think they’ve just downloaded another run-of-the-mill app, the malware is hard at work obtaining personal data.
In order to keep sensitive information out of the hands of cybercriminals, here are a few things users can look for when they need to determine whether an app is fact or fiction:
With so many types of malware out in the world, it’s hard to keep track of them all. But there is one in particular that mobile device users need to be keenly aware of called grayware. As a coverall term for software or code that sits between normal and malicious, grayware comes in many forms, such as adware, spyware or madware. While adware and spyware can sometimes operate simultaneously on infected computers, madware — or adware on mobile devices — infiltrates smartphones by hiding within rogue apps. Once a mobile device is infected with madware from a malicious app, ads can infiltrate almost every aspect on a user’s phone. Madware isn’t just annoying; it also is a security and privacy risk, as some threats will try to obtain users’ data. To avoid the annoyance, as well as the cybersecurity risks of grayware, users can prepare their devices with these cautionary steps:
The post Cybercrime’s Most Wanted: Four Mobile Threats that Might Surprise You appeared first on McAfee Blog.
During our threat hunting exercises in recent months, we’ve started to observe a distinguishing pattern of msiexec.exe usage across different endpoints. As we drilled down to individual assets, we found traces of a recently discovered malware called Raspberry Robin. The RedCanary Research Team first coined the name for this malware in their blog post, and Sekoia published a Flash Report about the activity under the name of QNAP Worm. Both articles offer great analysis of the malware’s behavior. Our findings support and enrich prior research on the topic.
Raspberry Robin is a worm that spreads over an external drive. After initial infection, it downloads its payload through msiexec.exe from QNAP cloud accounts, executes its code through rundll32.exe, and establishes a command and control (C2) channel through TOR connections.
Let’s walkthrough the steps of the kill-chain to see how this malware functions.
Raspberry Robin is delivered through infected external disks. Once attached, cmd.exe tries to execute commands from a file within that disk. This file is either a .lnk file or a file with a specific naming pattern. Files with this pattern exhibit a 2 to 5 character name with an usually obscure extension, including .swy, .chk, .ico, .usb, .xml, and .cfg. Also, the attacker uses an excessive amount of whitespace/non printable characters and changing letter case to avoid string matching detection techniques. Example command lines include:
File sample for delivery can be found in this URL:
https://www.virustotal.com/gui/file/04c13e8b168b6f313745be4034db92bf725d47091a6985de9682b21588b8bcae/relations
Next, we observe explorer.exe running with an obscure command line argument, spawned by a previous instance of cmd.exe. This obscure argument seems to take the name of an infected external drive or .lnk file that was previously executed. Some of the samples had values including USB, USB DISK, or USB Drive, while some other samples had more specific names. On every instance of explorer.exe we see that the adversary is changing the letter case to avoid detection:
After delivery and initial execution, cmd.exe spawns msiexec.exe to download the Raspberry Robin payload. It uses -q or /q together with standard installation parameter to operate quietly. Once again, mixed case letters are used to bypass detection:
As you can see above, URLs used for payload download have a specific pattern. Domains use 2 to 4 character names with obscure TLDs including .xyz, .hk, .info, .pw, .cx, .me, and more. URL paths have a single directory with a random string 11 characters long, followed by hostname and the username of the victim. On network telemetry, we also observed the Windows Installer user agent due to the usage of msiexec.exe. To detect Raspberry Robin through its URL pattern, use this regex:
^http[s]{0,1}\:\/\/[a-zA-Z0-9]{2,4}\.[a-zA-Z0-9]{2,6}\:8080\/[a-zA-Z0-9]+\/.*?(?:-|\=|\?).*?$
If we look up the WHOIS information for given domains, we see domain registration dates going as far back as February 2015. We also see an increase on registered domains starting from September 2021, which aligns with initial observations of Raspberry Robin by our peers.
WHOIS Creation Date | Count |
12/9/2015 | 1 |
… | … |
10/8/2020 | 1 |
11/14/2020 | 1 |
7/3/2021 | 1 |
7/26/2021 | 2 |
9/11/2021 | 2 |
9/23/2021 | 9 |
9/24/2021 | 6 |
9/26/2021 | 4 |
9/27/2021 | 2 |
11/9/2021 | 3 |
11/10/2021 | 1 |
11/18/2021 | 2 |
11/21/2021 | 3 |
12/11/2021 | 7 |
12/31/2021 | 7 |
1/17/2022 | 6 |
1/30/2022 | 11 |
1/31/2022 | 3 |
4/17/2022 | 5 |
Table 1: Distribution of domain creation dates over time
Associated domains have SSL certificates with the subject alternative name of q74243532.myqnapcloud.com, which points out the underlying QNAP cloud infra. Also, their URL scan results return login pages to QTS service of QNAP:
Once the payload is downloaded, it is executed through various system binaries. First, rundll32.exe uses the ShellExec_RunDLL function from shell32.dll to leverage system binaries such as msiexec.exe, odbcconf.exe, or control.exe. These binaries are used to execute the payload stored in C:\ProgramData\[3 chars]\
It is followed by the execution of fodhelper.exe, which has the auto elevated bit set to true. It is often leveraged by adversaries in order to bypass User Account Control and execute additional commands with escalated privileges [3]. To monitor suspicious executions of fodhelper.exe, we suggest monitoring its instances without any command line arguments.
Raspberry Robin sets up its C2 channel through the additional execution of system binaries without any command line argument, which is quite unusual. That likely points to process injection given elevated privileges in previous steps of execution. It uses dllhost.exe, rundll32.exe, and regsvr32.exe to set up a TOR connection.
In Cisco Global Threat Alerts available through Cisco Secure Network Analytics and Cisco Secure Endpoint, we track this activity under the Raspberry Robin threat object. Image 3 shows a detection sample of Raspberry Robin:
Raspberry Robin tries to remain undetected through its use of system binaries, mixed letter case, TOR-based C2, and abuse of compromised QNAP accounts. Although we have similar intelligence gaps (how it infects external disks, what are its actions on objective) like our peers, we are continuously observing its activities.
Type | Stage | IOC |
Domain | Payload Delivery | k6j[.]pw |
Domain | Payload Delivery | kjaj[.]top |
Domain | Payload Delivery | v0[.]cx |
Domain | Payload Delivery | zk4[.]me |
Domain | Payload Delivery | zk5[.]co |
Domain | Payload Delivery | 0dz[.]me |
Domain | Payload Delivery | 0e[.]si |
Domain | Payload Delivery | 5qw[.]pw |
Domain | Payload Delivery | 6w[.]re |
Domain | Payload Delivery | 6xj[.]xyz |
Domain | Payload Delivery | aij[.]hk |
Domain | Payload Delivery | b9[.]pm |
Domain | Payload Delivery | glnj[.]nl |
Domain | Payload Delivery | j4r[.]xyz |
Domain | Payload Delivery | j68[.]info |
Domain | Payload Delivery | j8[.]si |
Domain | Payload Delivery | jjl[.]one |
Domain | Payload Delivery | jzm[.]pw |
Domain | Payload Delivery | k6c[.]org |
Domain | Payload Delivery | kj1[.]xyz |
Domain | Payload Delivery | kr4[.]xyz |
Domain | Payload Delivery | l9b[.]org |
Domain | Payload Delivery | lwip[.]re |
Domain | Payload Delivery | mzjc[.]is |
Domain | Payload Delivery | nt3[.]xyz |
Domain | Payload Delivery | qmpo[.]art |
Domain | Payload Delivery | tiua[.]uk |
Domain | Payload Delivery | vn6[.]co |
Domain | Payload Delivery | z7s[.]org |
Domain | Payload Delivery | k5x[.]xyz |
Domain | Payload Delivery | 6Y[.]rE |
Domain | Payload Delivery | doem[.]Re |
Domain | Payload Delivery | bpyo[.]IN |
Domain | Payload Delivery | l5k[.]xYZ |
Domain | Payload Delivery | uQW[.]fUTbOL |
Domain | Payload Delivery | t7[.]Nz |
Domain | Payload Delivery | 0t[.]yT |