LOLSpoof is a an interactive shell program that automatically spoof the command line arguments of the spawned process. Just call your incriminate-looking command line LOLBin (e.g. powershell -w hidden -enc ZwBlAHQALQBwAHIAbwBjAGUA....
) and LOLSpoof will ensure that the process creation telemetry appears legitimate and clear.
Process command line is a very monitored telemetry, being thoroughly inspected by AV/EDRs, SOC analysts or threat hunters.
lolbin.exe " " * sizeof(real arguments)
Although this simple technique helps to bypass command line detection, it may introduce other suspicious telemetry: 1. Creation of suspended process 2. The new process has trailing spaces (but it's really easy to make it a repeated character or even random data instead) 3. Write to the spawned process with WriteProcessMemory
Built with Nim 1.6.12 (compiling with Nim 2.X yields errors!)
nimble install winim
Programs that clear or change the previous printed console messages (such as timeout.exe 10
) breaks the program. when such commands are employed, you'll need to restart the console. Don't know how to fix that, open to suggestions.
Trawler is a PowerShell script designed to help Incident Responders discover potential indicators of compromise on Windows hosts, primarily focused on persistence mechanisms including Scheduled Tasks, Services, Registry Modifications, Startup Items, Binary Modifications and more.
Currently, trawler can detect most of the persistence techniques specifically called out by MITRE and Atomic Red Team with more detections being added on a regular basis.
Just download and run trawler.ps1 from an Administrative PowerShell/cmd prompt - any detections will be displayed in the console as well as written to a CSV ('detections.csv') in the current working directory. The generated CSV will contain Detection Name, Source, Risk, Metadata and the relevant MITRE Technique.
Or use this one-liner from an Administrative PowerShell terminal:
iex ((New-Object System.Net.WebClient).DownloadString('https://raw.githubusercontent.com/joeavanzato/Trawler/main/trawler.ps1'))
Certain detections have allow-lists built-in to help remove noise from default Windows configurations (10/2016/2019/2022) - expected Scheduled Tasks, Services, etc. Of course, it is always possible for attackers to hijack these directly and masquerade with great detail as a default OS process - take care to use multiple forms of analysis and detection when dealing with skillful adversaries.
If you have examples or ideas for additional detections, please feel free to submit an Issue or PR with relevant technical details/references - the code-base is a little messy right now and will be cleaned up over time.
Additionally, if you identify obvious false positives, please let me know by opening an issue or PR on GitHub! The obvious culprits for this will be non-standard COMs, Services or Tasks.
-scanoptions : Tab-through possible detections and select a sub-set using comma-delimited terms (eg. .\trawler.ps1 -scanoptions Services,Processes)
-hide : Suppress Detection output to console
-snapshot : Capture a "persistence snapshot" of the current system, defaulting to "$PSScriptRoot\snapshot.csv"
-snapshotpath : Define a custom file-path for saving snapshot output to.
-outpath : Define a custom file-path for saving detection output to (defaults to "$PSScriptRoot\detections.csv")
-loadsnapshot : Define the path for an existing snapshot file to load as an allow-list reference
-drivetarget : Define the variable for a mounted target drive (eg. .\trawler.ps1 -targetdrive "D:") - using this alone leads to an 'assumed homedrive' variable of C: for analysis purposes
PersistenceSniper is an awesome tool - I've used it heavily in the past - but there are a few key points that differentiate these utilities
Overall, these tools are extremely similar but approach the problem from slightly different angles - PersistenceSniper provides all information back to the analyst for review while Trawler tries to limit what is returned to only results that are likely to be potential adversary persistence mechanisms. As such, there is a possibility for false-negatives with trawler if an adversary completely mimics an allow-listed item.
Trawler supports loading an allow-list from a 'snapshot' - to do this requires two steps.
That's it - all relevant detections will then draw from the snapshot file as an allow-list to reduce noise and identify any potential changes to the base image that may have occurred.
(Allow-listing is implemented for most of the checks but not all - still being actively implemented)
Often during an investigation, analysts may end up mounting a new drive that represents an imaged Windows device - Trawler now partially supports scanning these mounted drives through the use of the '-drivetarget' parameter.
At runtime, Trawler will re-target temporary script-level variables for use in checking file-based artifacts and also will attempt to load relevant Registry Hives (HKLM\SOFTWARE, HKLM\SYSTEM, NTUSER.DATs, USRCLASS.DATs) underneath HKLM/HKU and prefixed by 'ANALYSIS_'. Trawler will also attempt to unload these temporarily loaded hives upon script completion.
As an example, if you have an image mounted at a location such as 'F:\Test' which contains the NTFS file system ('F:\Test\Windows', 'F:\Test\User', etc) then you can invoke trawler like below;
.\trawler.ps1 -drivetarget "F:\Test"
Please note that since trawler attempts to load the registry hive files from the drive in question, mapping a UNC path to a live remote device will NOT work as those files will not be accessible due to system locks. I am working on an approach which will handle live remote devices, stay tuned.
Most other checks will function fine because they are based entirely on reading registry hives or file-based artifacts (or can be converted to do so, such as directly reading Task XML as opposed to using built-in command-lets.)
Any limitations in checks when doing drive-retargeting will be discussed more fully in the GitHub Wiki.
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TODO
Please be aware that some of these are (of course) more detected than others - for example, we are not detecting all possible registry modifications but rather inspecting certain keys for obvious changes and using the generic MITRE technique "Modify Registry" where no other technique is applicable. For other items such as COM hijacking, we are inspecting all entries in the relevant registry section, checking against 'known-good' patterns and bubbling up unknown or mismatched values, resulting in a much more complete detection surface for that particular technique.
This tool would not exist without the amazing InfoSec community - the most notable references I used are provided below.
Authored By Tyl0us
Featured at Source Zero Con 2022
Mangle is a tool that manipulates aspects of compiled executables (.exe or DLL). Mangle can remove known Indicators of Compromise (IoC) based strings and replace them with random characters, change the file by inflating the size to avoid EDRs, and can clone code-signing certs from legitimate files. In doing so, Mangle helps loaders evade on-disk and in-memory scanners.
Mangle was developed in Golang.
The first step, as always, is to clone the repo. Before you compile Mangle, you'll need to install the dependencies. To install them, run the following commands:
go get github.com/Binject/debug/pe
Then build it
go build Mangle.go
While Mangle is written in Golang, a lot of the features are designed to work on executable files from other languages. At the time of release, the only feature that is Golang specific is the string manipulation part.
./mangle -h
_____ .__
/ \ _____ ____ ____ | | ____
/ \ / \\__ \ / \ / ___\| | _/ __ \
/ Y \/ __ \| | \/ /_/ > |_\ ___/
\____|__ (____ /___| /\___ /|____/\___ >
\/ \/ \//_____/ \/
(@Tyl0us)
Usage of ./Mangle:
-C string
Path to the file containing the certificate you want to clone
-I string
Path to the orginal file
-M Edit the PE file to strip out Go indicators
-O string
The new file name
-S int
How many MBs to increase the file by
Mangle takes the input executable and looks for known strings that security products look for or alert on. These strings alone are not the sole point of detection. Often, these strings are in conjunction with other data points and pieces of telemetry for detection and prevention. Mangle finds these known strings and replaces the hex values with random ones to remove them. IMPORTANT: Mangle replaces the exact size of the strings itβs manipulating. It doesnβt add any more or any less, as this would create misalignments and instabilities in the file. Mangle does this using the -M
command-line option.
Currently, Mangle only does Golang files but as time goes on other languages will be added. If you know of any for other languages, please open an issue ticket and submit them.
Before
Β
After
Pretty much all EDRs canβt scan both on disk or in memory files beyond a certain size. This simply stems from the fact that large files take longer to review, scan, or monitor. EDRs do not want to impact performance by slowing down the user's productivity. Mangle inflates files by creating a padding of Null bytes (Zeros) at the end of the file. This ensures that nothing inside the file is impacted. To inflate an executable, use the -S
command-line option along with the number of bytes you want to add to the file. Large payloads are really not an issue anymore with how fast Internet speeds are, that being said, it's not recommended to make a 2 gig file.
Based on test cases across numerous userland and kernel EDRs, it is recommended to increase the size by either 95-100 megabytes. Because vendors do not check large files, the activity goes unnoticed, resulting in the successful execution of shellcode.
Mangle also contains the ability to take the full chain and all attributes from a legitimate code-signing certificate from a file and copy it onto another file. This includes the signing date, counter signatures, and other measurable attributes.
While this feature may sound similar to another tool I developed, Limelighter, the major difference between the two is that Limelighter makes a fake certificate based off a domain and signs it with the current date and time, versus using valid attributes where the timestamp is taken from when the original file. This option can use DLL or .exe files to copy using the -C
command-line option, along with the path to the file you want to copy the certificate from.