Rewterz Threat Alert – LockBit 3.0 Ransomware Spreads Via Word Documents – 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, 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.

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. 

Recently, 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.

An image in the document file triggers the execution of a macro script. When the user selects Enable Content on the downloaded dlx5rc.dotm, a malicious VBA macro script is launched.

Additional malicious files are obtained from hxxp:/ppaauuaa11232[.]cc/aaa.exe using PowerShell commands when the link file is run, and they are then saved in C:\Users\Public\156498415616651651984561561658456.exe before being executed.

LockBit 3.0 ransomware in NSIS form is present in the downloaded 156498415616651651984561561658456.exe file.

source

Impact

• Security Bypass
• Information Theft
• Files Encryption

Indicators of Compromise

MD5

• 7b74e4fb9a95f41d5d9b4a71a5fe40b9

SHA-256

• 0ec87a7f943ab72d08aeb957d33dd348ab7cf45052ab7a31bcce33ff7a095837

SHA1

• ff3e85fec483c637774101194c52a17a6a0598ef

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 Indicator 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.