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. DJVU Ransomware is a type of malicious software that encrypts the files on an infected computer and demands a ransom payment in exchange for the decryption key. The STOP/DJVU Ransomware family is one of the most prevalent ransomware threats and is known for its aggressive tactics and high-pressure ransom demands.

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.

ransom note

Impact

• Information Theft
• File Encryption

Indicators of Compromise

MD5

• 561bd76cefe9b3429eeaa2aec1bcc96f
• db6bea3bdd091420e5a3eefec039da84
• 0a23310ed03ca85389e5738e00490bd5

SHA-256

• 959218473693d550912d906d2fc3d09f98c2a19dc7e5a09a09fb932c7fa25c3c
• 83513ead85629fb300aba6a80e3a110031b7c8c51ff13029459e720169c20b09
• 7dc3815a0db7fc813d9927f7a938cdb506d9c828505714d4a2dd2ab4686a50f9

SHA-1

• a47fa3e39780b470c5687d9460214d0f1ec462a0
• 4db2426662244410565efea98337d0041e17fae7
• 159677590ed0a137529be4d3df42fe961d640808

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.
• Patch and upgrade any platforms and software timely and make it into a standard security policy. Prioritize patching known exploited vulnerabilities and zero-days.
• Along with network and system hardening, code hardening should be implemented within the organization so that their websites and software are secure. Use testing tools to detect any vulnerabilities in the deployed codes.
• Enable antivirus and anti-malware software and update signature definitions in a timely manner. Using multi-layered protection is necessary to secure vulnerable assets