Rewterz Threat Alert – STOP (DJVU) Ransomware – Active IOCs

Severity

High

Analysis Summary

The STOP/DJVU ransomware initially made headlines in 2018 and has since been attacking individuals all around the world. It’s widespread on torrent sites and other platforms in software crack packages and adware bundles. The STOP/DJVU ransomware is a Trojan that encrypts files. It infiltrates your computer invisibly and encrypts all of your data, making them unavailable to you. It leaves a ransom letter warning which demands money in exchange for decrypting your data and making them available to you again. Malware is delivered via cracked applications, fake set-up apps keygens, activators, and Windows updates. It does not utilize local information like keyboard layouts or timezone settings to prevent infecting victims in certain countries; instead, it uses the information returned by a request to https[:]//api.2ip.ua/geo.json. The card’s MAC address is utilized to provide unique identification for the system. This identity is provided to STOP’s command and control server, which responded with an RSA-2048 public key for encryption. Additional malware, including an information stealer known as Vidar, is then downloaded and installed.

Impact

• Information Theft
• File Encryption

Indicators of Compromise

MD5

• 837b8b55d7670cc0f6834bb48dc78b22
• 94ade61c17d4cb27161846ca0d3afb6b

SHA-256

• 29f97b0d4193e20257d182afbaf48a3fffdc8193a8520fc8cf4a501df40efe82
• 11622e1a045939b729512c66cf36d2d49a6d379185f242f3fb6897aabb3933b8

SHA-1

• 86bdf1fbea6b79f942e9ed27465d9df465fea2ca
• dc1d8db4d54a28b173b13b699c9b9666455774e5

Remediation

• Block all threat indicators at your respective controls.
• Search for Indicators of compromise (IOCs) in your environment utilizing your respective security controls
• Maintain cyber hygiene by updating your anti-virus software and implementing a patch management lifecycle.
• Maintain Offline Backups – In a ransomware attack, the adversary will often delete or encrypt backups if they have access to them. That’s why it’s important to keep offline (preferably off-site), encrypted backups of data and test them regularly.
• Emails from unknown senders should always be treated with caution.
• Never trust or open ” links and attachments received from unknown sources/senders