SloppyRAT: A New Tool For Ransomware Attacks
Zscaler details SloppyRAT, a new DLL backdoor delivered via ClickFix lures that stages CastleLoader and CastleRAT ahead of ransomware attacks.
Zscaler ThreatLabz analyzed SloppyRAT, a DLL-based backdoor distributed via ClickFix lures that abuses finger.exe over TCP port 79 to download a batch script. The malware copies curl.exe to download IronPython 3.4.2 from GitHub and executes zlib-compressed Base64-encoded Python to deploy CastleLoader and CastleRAT, then reflectively loads SloppyRAT in memory. It hinders analysis using XOR stack-string obfuscation, a modified affine cipher with modulus 127, and 13 runtime-decrypted code blocks, while communicating with C2 over a reverse SOCKS channel.
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