The Interlock ransomware gang now makes use of ClickFix assaults that impersonate IT instruments to breach company networks and deploy file-encrypting malware on gadgets.
ClickFix is a social engineering tactic the place victims are tricked into executing harmful PowerShell instructions on their methods to supposedly repair an error or confirm themselves, ensuing within the set up of malware.
Although this is not the primary time ClickFix has been linked to ransomware infections, affirmation about Interlock exhibits an growing development in some of these menace actors using the tactic.
Interlock is a ransomware operation launched in late September 2024, focusing on FreeBSD servers and Home windows methods.
Interlock will not be believed to function as a ransomware-as-a-service mannequin. Nonetheless, it maintains a knowledge leak portal on the darkish net to extend stress on victims, demanding funds starting from lots of of hundreds of {dollars} to tens of millions.
From ClickFix to ransomware
Prior to now, Interlock utilized pretend browser and VPN shopper updates to put in malware and breach networks.
Based on Sekoia researchers, the Interlock ransomware gang started using ClickFix assaults in January 2025.
Interlock used no less than 4 URLs to host pretend CAPTCHA prompts that inform guests to execute a command on their pc to confirm themselves and obtain a promoted device.
The researchers say they detected the malicious captcha on 4 completely different websites, mimicking Microsoft or Superior IP Scanner portals:
- microsoft-msteams[.]com/additional-check.html
- microstteams[.]com/additional-check.html
- ecologilives[.]com/additional-check.html
- advanceipscaner[.]com/additional-check.html
Nevertheless, solely the location impersonating Superior IP Scanner, a well-liked IP scanning device generally utilized by IT employees, led to downloading a malicious installer.
Supply: Sekoia
Clicking the ‘Repair it’ button copies the malicious PowerShell command to the sufferer’s clipboard. If executed in a command immediate or Home windows Run dialog, it should obtain a 36MB PyInstaller payload.
On the identical time, the reliable AdvanceIPScanner web site opens in a browser window to cut back suspicion.
The malicious payload installs a reliable copy of the software program it pretends to be and concurrently executes an embedded PowerShell script that runs in a hidden window.
This script registers a Run key in Home windows Registry for persistence after which collects and exfiltrates system data together with OS model, consumer privilege degree, working processes, and obtainable drives.
Sekoia has noticed the command and management (C2) responding with numerous payloads, together with LummaStealer, BerserkStealer, keyloggers, and the Interlock RAT.
The latter is a straightforward trojan that may be dynamically configured, supporting file exfiltration, shell command execution, and working malicious DLLs.
Supply: Sekoia
After the preliminary compromise and RAT deployment, Interlock operators used stolen credentials to maneuver laterally through RDP, whereas Sekoia additionally noticed PuTTY, AnyDesk, and LogMeIn utilized in some assaults.
The final step earlier than the ransomware execution is information exfiltration, with the stolen information uploaded to attacker-controlled Azure Blobs.
The Home windows variant of Interlock is ready (through a scheduled job) to run every day at 08:00 PM, however due to file extension-based filtering, this does not trigger a number of layers of encryption however serves as a redundancy measure.
Sekoia additionally experiences that the ransom notice has developed, too, with the newest variations focusing extra on the authorized side of the info breach and the regulatory penalties if stolen information is made public.
Supply: BleepingComputer
ClickFix assaults have now been adopted by a variety of menace actors, together with different ransomware gangs and North Korean hackers.
Final month, Sekoia found that the notorious Lazarus North Korean hacking group was utilizing ClickFix assaults focusing on job seekers within the cryptocurrency business.
