Rewterz Threat Alert – Virlock Ransomware – Active IOCs

Severity

High

Analysis Summary

Virlock is a file-infecting ransomware that was initially found in 2014 but reappeared in 2016 and 2017. Virlock revealed new abilities with each reappearance, showing that the threat actors are continually developing and updating the malware. It showed unique capabilities in 2016 that allowed it to expand through shared apps and cloud storage. During the initial stage of its attack, this ransomware drops three instances of itself, each with its own obfuscation and persistence techniques. By altering the functionality implemented by each instance, Virlock ensures that all three instances can evade a signature-based detection system. Virlock, like other ransomware, demands payment in Bitcoin from the victim in order to decrypt their machines.

Impact

• File Encryption

Indicators of Compromise

MD5

• 91feb4b65f782388a50d99ba36368fe2

SHA-256

• 3c8693b21660fb2989f840c2053292e5d1d3f98377f3569c3927a8a57170ab18

SHA-1

• 4baa52eb40ef42a998539575fbe97dfc2ffd32a0

Remediation

• Block all threat indicators at your respective controls.
• Search for IOCs in your environment.