Rewterz Threat Alert – LockBit Ransomware Being Distributed Using Similar Filenames – Active IOCs

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, researchers 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.

LockBit strives to target different sectors throughout the world and has just rebranded for the second time. Operators and affiliates behind the LockBit ransomware started transitioning to LockBit 3.0 around June 2022. LockBit 3.0, also known as LockBit Black, is active and out there, and the BFSI Sector makes up 1/3rd of its victims. This latest LockBit version has a new extortion model that allows them to purchase stolen data during attacks. Rapid affiliate adoption of LockBit 3.0 has resulted in a large number of victims being identified on the new “Version 3.0” leak sites, a collection of public blogs that identify non-compliant victims and release extracted data.

In September 2022, researchers discovered that LockBit 3.0 ransomware is being delivered in Word document format while masquerading as job application emails in NSIS format.

The particular distribution method has not yet been discovered, but given that the file names include people’s names, such as ‘Lim Gyu Min.docx’ or ‘Jeon Chae Rin.docx,’ it is possible that they were spread disguised as job applications, as in previous occurrences.

It was recently discovered that LockBit 2.0 and LockBit 3.0 are being distributed once more with merely a filename change. The recent versions are being delivered using phishing emails that seem like job applications, compared to earlier examples where word files or emails with copyright claims were utilized.

source

LockBit has recently been distributed without restriction to version or identical filename. 

Therefore, users must examine the file extensions of document files, update apps and V3 to the newest version, and be very cautious when opening files from unidentified sources.

Impact

• Security Bypass
• Information Theft
• Files Encryption

Indicators of Compromise

MD5

48aa442a0670b65a82eee99c1ed1ac78
b303ffe0bbddca1570940557cabdd966

SHA-256

f6fbfa9fe38f69f8806d60072b7e8a9aceacf4a2b27095f7297f529ba986eab4
5e79854b8a92b169212e0ea3ad0252e4a86fc7e186fc162f143bb7754a73ec63

SHA-1

12117609b746257a6cdd2808dcb50c6af9c1810d
647b9aeb909e9900a07a1796d764469ad71ddf2e

Remediation

• Users should upgrade their applications and V3 to the most recent version and avoid opening documents from unknown sources.
• 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 implement 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.