Severity
High
Analysis Summary
LockBit ransomware takes as little as five minutes to deploy the encryption routine on target systems once it lands on the victim network. LockBit attacks leave few traces for forensic analysis as the malware loads into the system memory, with logs and supporting files removed upon execution. In one case, they found that the attack began from a compromised Internet Information Server that launched a remote PowerShell script calling another script embedded in a remote Google Sheets document. This script connects to a command and control server to retrieve and install a PowerShell module for adding a backdoor and establish persistence. To evade monitoring and go unnoticed in the logs, the attacker renamed copies of PowerShell and the binary for running Microsoft HTML Applications (mshta.exe); this prompted Sophos to call this a “PS Rename“ attack. The backdoor is responsible for installing attack modules and executes a VBScript that downloads and executes a second backdoor on systems restart.
Impact
- Security Bypass
- Information Theft
- Files Encryption
Indicators of Compromise
MD5
- 40579507ed71fa7798ef3f08ab98837a
- d31a611c145ca652e101723ea61761d2
SHA-256
- 44f5465e2c89ddee628048b102516b6d18f78d55ace1e425ab70ab13ac74f7df
- d10ffa270a1812dfc5cd333fd6a3e18a0e28bf28f4404a3447c566582a5bf657
SHA-1
- 126e3bfd0a4f2b8fc4f2eabdde6fd88ac28a8eb2
- ab3613c9efc26248f5f3f88deeb509aac4042167
Remediation
- Block all threat indicators at their respective controls.
- Do not respond to emails coming from untrusted sources.
- Do not open untrusted files received by any means.