211. That's How Stealers Defeat System Recovery

Hello everyone!

What's the first thing you think about hearing about defeating system recovery? Ransomware? Sure, but it's not the only case. And you can transform it into a detection opportunity!

Elastic Security Labs presented a report on NOVABLIGHT - a NodeJS infostealer. It has a lot of features, but we're going to look at those related to defeating system recovery.

For example, the stealer disables the Windows Recovery Environment (reagentc /disable) and deletes all Volume Shadow Copies (vssadmin delete shadows /all).

And here we have two detection opportunities, disabling WRE:

event_type: "processcreatewin"

AND

proc_file_path: "reagentc.exe"

AND

cmdline: "disable"

And deleting WSC:

event_type: "processcreatewin"

AND

proc_file_path: "vssadmin.exe"

AND

cmdline: ("delete" AND "shadows")

See you tomorrow!

Comments

Post a Comment

Popular posts from this blog

343. Ransomware Gangs Abuse SystemSettingsAdminFlows to Evade Defenses

Image
Hello everyone! Today we'll look at another example of how adversaries abuse legitimate Windows executables to evade defenses. This time it's  SystemSettingsAdminFlows.exe . According to this report , DeadLock leveraged this utility to disable various features of Windows Defender: SystemSettingsAdminFlows.exe Defender RTP 1  SystemSettingsAdminFlows.exe Defender SpynetReporting 0  SystemSettingsAdminFlows.exe Defender SubmitSamplesConsent 0  SystemSettingsAdminFlows.exe Defender DisableEnhancedNotifications 1 The commands disable Real-Time Protection (RTP) and cloud-based protections, stops the machine from sending threat reports to Microsoft, and prevent Windows Defender from automatically submitting suspicious files for analysis. Worth a query, isn't it? event_type: "processcreatewin" AND proc_file_path: "systemsettingsadminflows.exe" AND cmdline: "defender" See you tomorrow!
Read more

391. Hunting for TeamPCP's Stealer

Image
Hello everyone! What do I know about stealers? They seem to be very noisy! And today, we’ll once again see that in action using TeamPCP (Haze Wolf) as an example. This time , the stealer was implanted by attackers into three versions of the xinference package (2.6.0, 2.6.1, and 2.6.2). Essentially, it collects SSH keys, various credentials, environment variables, crypto wallets, and much more, then uses cURL for exfiltration. Let’s take a look at a couple of techniques the attackers used to obtain credentials. For example, they were interested in data stored in environment variables: env | grep AWS_ env | grep -i google env | grep -i gcloud env | grep -i azure This looks fairly suspicious from a detection perspective: event_type: processcreate* AND proc_file_path: "env" AND cmdline: ("grep" AND ("aws_" OR "google" OR "azure" OR "gcloud")) Another technique was abusing kubectl to obtain credentials: kubectl get secrets --all-n...
Read more

082. Huniting for Malicious Browser Extensions

Image
Hello everyone! Malicious browser extensions are stopping to be an exotic threat. For example,  Rilide . It was first reported in April 2023, but became a common threat, and this report is another proof of it. Can we hunt for such extensions? Of course, yes! For example, usually threats like Rilide modify browser-reated LNK files to run it with " --load-extension " argument, like this: chrome.exe --load-extension="C:\Users\user\AppData\Local\Temp\MalExt" It means we can hunt for execution of common Chromium-based browsers with this argument: event_type: "processcreatewin" AND proc_file_name: ("chrome.exe" OR "brave.exe" OR "opera.exe" OR "msedge.exe")  AND cmdline: "load-extension" I'm sure you'll get false positives, but this is what we expect from threat hunting, right? Proper filtering will help you, I'm sure! See you tomorrow!
Read more