A campaign promoting the long-standing.NET keylogger and remote access trojan (RAT) known as Agent Tesla uses a program that is available on the dark web that enables attackers to create harmful shortcuts for distributing malware.
In the campaign that the experts observed, malicious hackers were using the developer to generate malicious LNK, HTA, and PowerShell payloads used to produce Agent Tesla on the targeted servers. The Quantum Builder also enables the creation of malicious HTA, ISO, and PowerShell payloads which are used to drop the next-stage malware.
When compared to previous attacks, experts have found that this campaign has improved and shifted toward LNK, and Windows shortcut files.
A spear-phishing email with a GZIP archive is swapped out for a ZIP file in a second round of the infection sequence, which also uses other obfuscation techniques to mask the harmful behavior.
The shortcut to run PowerShell code that launches a remote HTML application (HTA) using MSHTA is the first step in the multi-stage attack chain. In turn, the HTA file decrypts and runs a different PowerShell loader script, which serves as a downloader for the Agent Tesla malware and runs it with administrative rights.
Quantum Builder, which can be bought on the dark web for €189 a month, has recently witnessed an increase in its use, with threat actors utilizing it to disseminate various malware, including RedLine Stealer, IcedID, GuLoader, RemcosRAT, and AsyncRAT.
Malicious hackers often change their tactics and use spyware creators bought and sold on the black market for crimes. This Agent Tesla effort is the most recent in a series of assaults in which harmful payloads were created using Quantum Builder in cyber campaigns against numerous companies.
It features advanced evasion strategies, and the developers frequently upgrade these techniques. To keep its clients safe, the Zscaler ThreatLabz team would continue to track these cyberattacks.
Agent Tesla, one of the most notorious keyloggers used by hackers, was shut down on March 4, 2019, due to legal issues. It is a remote access program built on the.NET platform, that has long existed in the cyber realm, enabling malicious actors to obtain remote access to target devices and transmit user data to a domain under their control. It has been in the public since 2014 and is promoted for sale on dark web forums.
In a recent attack, OriginLogger, a malware that was hailed as the replacement for the well-known data theft and remote access trojan (RAT) noted as Agent Tesla, had its functioning dissected by Palo Alto Networks Unit 42.
