The U.S. government on Wednesday announced the arrest and charging of two Sudanese brothers accused of running Anonymous Sudan (a.k.a. AnonSudan), a cybercrime business known for launching powerful distributed denial-of-service (DDoS) attacks against a range of targets, including dozens of hospitals, news websites and cloud providers. The younger brother is facing charges that could land him life in prison for allegedly seeking to kill people with his attacks.
Image: FBI
Active since at least January 2023, AnonSudan has been described in media reports as a “hacktivist” group motivated by ideological causes. But in a criminal complaint, the FBI said those high-profile cyberattacks were effectively commercials for the hackers’ DDoS-for-hire service, which they sold to paying customers for as little as $150 a day — with up to 100 attacks allowed per day — or $700 for an entire week.
The complaint says despite reports suggesting Anonymous Sudan might be state-sponsored Russian actors pretending to be Sudanese hackers with Islamist motivations, AnonSudan was led by two brothers in Sudan — Ahmed Salah Yousif Omer, 22, and Alaa Salah Yusuuf Omer, 27.
AnonSudan claimed credit for successful DDoS attacks on numerous U.S. companies, causing a multi-day outage for Microsoft’s cloud services in June 2023. The group hit PayPal the following month, followed by Twitter/X (Aug. 2023), and OpenAI (Nov. 2023). An indictment in the Central District of California notes the duo even swamped the websites of the FBI and the Department of State.
Prosecutors say Anonymous Sudan offered a “Limited Internet Shutdown Package,” which would enable customers to shut down internet service providers in specified countries for $500 (USD) an hour. The two men also allegedly extorted some of their victims for money in exchange for calling off DDoS attacks.
The government isn’t saying where the Omer brothers are being held, only that they were arrested in March 2024 and have been in custody since. A statement by the U.S. Department of Justice says the government also seized control of AnonSudan’s DDoS infrastructure and servers after the two were arrested in March.
AnonSudan accepted orders over the instant messaging service Telegram, and marketed its DDoS service by several names, including “Skynet,” “InfraShutdown,” and the “Godzilla botnet.” However, the DDoS machine the Omer brothers allegedly built was not made up of hacked devices — as is typical with DDoS botnets.
Instead, the government alleges Skynet was more like a “distributed cloud attack tool,” with a command and control (C2) server, and an entire fleet of cloud-based servers that forwards C2 instructions to an array of open proxy resolvers run by unaffiliated third parties, which then transmit the DDoS attack data to the victims.
Amazon was among many companies credited with helping the government in the investigation, and said AnonSudan launched its attacks by finding hosting companies that would rent them small armies of servers.
“Where their potential impact becomes really significant is when they then acquire access to thousands of other machines — typically misconfigured web servers — through which almost anyone can funnel attack traffic,” Amazon explained in a blog post. “This extra layer of machines usually hides the true source of an attack from the targets.”
The security firm CrowdStrike said the success of AnonSudan’s DDoS attacks stemmed from a combination of factors, including sophisticated techniques for bypassing DDoS mitigation services. Also, AnonSudan typically launched so-called “Layer 7” attacks that sought to overwhelm targeted “API endpoints” — the back end systems responsible for handling website requests — with bogus requests for data, leaving the target unable to serve legitimate visitors.
The Omer brothers were both charged with one count of conspiracy to damage protected computers. The younger brother — Ahmed Salah — was also charged with three counts of damaging protected computers.
A passport for Ahmed Salah Yousif Omer. Image: FBI.
If extradited to the United States, tried and convicted in a court of law, the older brother Alaa Salah would be facing a maximum of five years in prison. But prosecutors say Ahmed Salah could face life in prison for allegedly launching attacks that sought to kill people.
As Hamas fighters broke through the border fence and attacked Israel on Oct. 7, 2023, a wave of rockets was launched into Israel. At the same time, AnonSudan announced it was attacking the APIs that power Israel’s widely-used “red alert” mobile apps that warn residents about any incoming rocket attacks in their area.
In February 2024, AnonSudan launched a digital assault on the Cedars-Sinai Hospital in the Los Angeles area, an attack that caused emergency services and patients to be temporarily redirected to different hospitals.
The complaint alleges that in September 2023, AnonSudan began a week-long DDoS attack against the Internet infrastructure of Kenya, knocking offline government services, banks, universities and at least seven hospitals.
Malicious hackers are exploiting a zero-day vulnerability in Versa Director, a software product used by many Internet and IT service providers. Researchers believe the activity is linked to Volt Typhoon, a Chinese cyber espionage group focused on infiltrating critical U.S. networks and laying the groundwork for the ability to disrupt communications between the United States and Asia during any future armed conflict with China.
Image: Shutterstock.com
Versa Director systems are primarily used by Internet service providers (ISPs), as well as managed service providers (MSPs) that cater to the IT needs of many small to mid-sized businesses simultaneously. In a security advisory published Aug. 26, Versa urged customers to deploy a patch for the vulnerability (CVE-2024-39717), which the company said is fixed in Versa Director 22.1.4 or later.
Versa said the weakness allows attackers to upload a file of their choosing to vulnerable systems. The advisory placed much of the blame on Versa customers who “failed to implement system hardening and firewall guidelines…leaving a management port exposed on the internet that provided the threat actors with initial access.”
Versa’s advisory doesn’t say how it learned of the zero-day flaw, but its vulnerability listing at mitre.org acknowledges “there are reports of others based on backbone telemetry observations of a 3rd party provider, however these are unconfirmed to date.”
Those third-party reports came in late June 2024 from Michael Horka, senior lead information security engineer at Black Lotus Labs, the security research arm of Lumen Technologies, which operates one of the global Internet’s largest backbones.
In an interview with KrebsOnSecurity, Horka said Black Lotus Labs identified a web-based backdoor on Versa Director systems belonging to four U.S. victims and one non-U.S. victim in the ISP and MSP sectors, with the earliest known exploit activity occurring at a U.S. ISP on June 12, 2024.
“This makes Versa Director a lucrative target for advanced persistent threat (APT) actors who would want to view or control network infrastructure at scale, or pivot into additional (or downstream) networks of interest,” Horka wrote in a blog post published today.
Black Lotus Labs said it assessed with “medium” confidence that Volt Typhoon was responsible for the compromises, noting the intrusions bear the hallmarks of the Chinese state-sponsored espionage group — including zero-day attacks targeting IT infrastructure providers, and Java-based backdoors that run in memory only.
In May 2023, the National Security Agency (NSA), the Federal Bureau of Investigation (FBI), and the Cybersecurity Infrastructure Security Agency (CISA) issued a joint warning (PDF) about Volt Typhoon, also known as “Bronze Silhouette” and “Insidious Taurus,” which described how the group uses small office/home office (SOHO) network devices to hide their activity.
In early December 2023, Black Lotus Labs published its findings on “KV-botnet,” thousands of compromised SOHO routers that were chained together to form a covert data transfer network supporting various Chinese state-sponsored hacking groups, including Volt Typhoon.
In January 2024, the U.S. Department of Justice disclosed the FBI had executed a court-authorized takedown of the KV-botnet shortly before Black Lotus Labs released its December report.
In February 2024, CISA again joined the FBI and NSA in warning Volt Typhoon had compromised the IT environments of multiple critical infrastructure organizations — primarily in communications, energy, transportation systems, and water and wastewater sectors — in the continental and non-continental United States and its territories, including Guam.
“Volt Typhoon’s choice of targets and pattern of behavior is not consistent with traditional cyber espionage or intelligence gathering operations, and the U.S. authoring agencies assess with high confidence that Volt Typhoon actors are pre-positioning themselves on IT networks to enable lateral movement to OT [operational technology] assets to disrupt functions,” that alert warned.
In a speech at Vanderbilt University in April, FBI Director Christopher Wray said China is developing the “ability to physically wreak havoc on our critical infrastructure at a time of its choosing,” and that China’s plan is to “land blows against civilian infrastructure to try to induce panic.”
Ryan English, an information security engineer at Lumen, said it’s disappointing his employer didn’t at least garner an honorable mention in Versa’s security advisory. But he said he’s glad there are now a lot fewer Versa systems exposed to this attack.
“Lumen has for the last nine weeks been very intimate with their leadership with the goal in mind of helping them mitigate this,” English said. “We’ve given them everything we could along the way, so it kind of sucks being referenced just as a third party.”
A 26-year-old Finnish man was sentenced to more than six years in prison today after being convicted of hacking into an online psychotherapy clinic, leaking tens of thousands of patient therapy records, and attempting to extort the clinic and patients.
On October 21, 2020, the Vastaamo Psychotherapy Center in Finland became the target of blackmail when a tormentor identified as “ransom_man” demanded payment of 40 bitcoins (~450,000 euros at the time) in return for a promise not to publish highly sensitive therapy session notes Vastaamo had exposed online.
Ransom_man announced on the dark web that he would start publishing 100 patient profiles every 24 hours. When Vastaamo declined to pay, ransom_man shifted to extorting individual patients. According to Finnish police, some 22,000 victims reported extortion attempts targeting them personally, targeted emails that threatened to publish their therapy notes online unless paid a 500 euro ransom.
Finnish prosecutors quickly zeroed in on a suspect: Julius “Zeekill” Kivimäki, a notorious criminal hacker convicted of committing tens of thousands of cybercrimes before he became an adult. After being charged with the attack in October 2022, Kivimäki fled the country. He was arrested four months later in France, hiding out under an assumed name and passport.
Antti Kurittu is a former criminal investigator who worked on an investigation involving Kivimäki’s use of the Zbot botnet, among other activities Kivimäki engaged in as a member of the hacker group Hack the Planet (HTP).
Kurittu said the prosecution had demanded at least seven years in jail, and that the sentence handed down was six years and three months. Kurittu said prosecutors knocked a few months off of Kivimäki’s sentence because he agreed to pay compensation to his victims, and that Kivimäki will remain in prison during any appeal process.
“I think the sentencing was as expected, knowing the Finnish judicial system,” Kurittu told KrebsOnSecurity. “As Kivimäki has not been sentenced to a non-suspended prison sentence during the last five years, he will be treated as a first-timer, his previous convictions notwithstanding.”
But because juvenile convictions in Finland don’t count towards determining whether somebody is a first-time offender, Kivimäki will end up serving approximately half of his sentence.
“This seems like a short sentence when taking into account the gravity of his actions and the life-altering consequences to thousands of people, but it’s almost the maximum the law allows for,” Kurittu said.
Kivimäki initially gained notoriety as a self-professed member of the Lizard Squad, a mainly low-skilled hacker group that specialized in DDoS attacks. But American and Finnish investigators say Kivimäki’s involvement in cybercrime dates back to at least 2008, when he was introduced to a founding member of what would soon become HTP.
Finnish police said Kivimäki also used the nicknames “Ryan”, “RyanC” and “Ryan Cleary” (Ryan Cleary was actually a member of a rival hacker group — LulzSec — who was sentenced to prison for hacking).
Kivimäki and other HTP members were involved in mass-compromising web servers using known vulnerabilities, and by 2012 Kivimäki’s alias Ryan Cleary was selling access to those servers in the form of a DDoS-for-hire service. Kivimäki was 15 years old at the time.
In 2013, investigators going through devices seized from Kivimäki found computer code that had been used to crack more than 60,000 web servers using a previously unknown vulnerability in Adobe’s ColdFusion software. KrebsOnSecurity detailed the work of HTP in September 2013, after the group compromised servers inside data brokers LexisNexis, Kroll, and Dun & Bradstreet.
The group used the same ColdFusion flaws to break into the National White Collar Crime Center (NWC3), a non-profit that provides research and investigative support to the U.S. Federal Bureau of Investigation (FBI).
As KrebsOnSecurity reported at the time, this small ColdFusion botnet of data broker servers was being controlled by the same cybercriminals who’d assumed control over SSNDOB, which operated one of the underground’s most reliable services for obtaining Social Security Number, dates of birth and credit file information on U.S. residents.
Kivimäki was responsible for making an August 2014 bomb threat against former Sony Online Entertainment President John Smedley that grounded an American Airlines plane. Kivimäki also was involved in calling in multiple fake bomb threats and “swatting” incidents — reporting fake hostage situations at an address to prompt a heavily armed police response to that location.
Ville Tapio, the former CEO of Vastaamo, was fired and also prosecuted following the breach. Ransom_man bragged about Vastaamo’s sloppy security, noting the company had used the laughably weak username and password “root/root” to protect sensitive patient records.
Investigators later found Vastaamo had originally been hacked in 2018 and again in 2019. In April 2023, a Finnish court handed down a three-month sentence for Tapio, but that sentence was suspended because he had no previous criminal record.