The Malware Is Apparently Making Use of Malicious Chrome Extensions.
Last updated on June 30, 2022
Chaes is a banking trojan that was discovered in Brazil in November 2020 and has been active since then.
The researchers at Avast were the ones that discovered Chaes’s artifacts on more than 800 websites in total.
More than 700 of them are based on TLDs from Brazil. All of the affected websites are WordPress-based, meaning that the attack vector may have been the exploitation of vulnerabilities in the WordPress content management system.
An interesting characteristic of Chaes is its multi-stage distribution method, which makes use of programming frameworks such as JScript, Python, and NodeJS, binary files written in Delphi, as well as malicious Google Chrome extensions, among other things. Chaes’s ultimate objective is to steal passwords saved in Chrome and intercept logins to prominent financial websites in Brazil.
Over 800 infected WordPress websites are being used in a large-scale operation to disseminate banking trojans that are designed to steal the credentials of Brazilian e-banking customers.
When victims visit one of the hacked websites, they are greeted with a pop-up window that instructs them to download and install a bogus Java Runtime application (JRE).
This is accomplished via the use of the scheduled.js script, which creates a Scheduled Task and a Startup link, and the sucesso.js script, which is responsible for reporting status to the C2.
The Python loader chain unfolds in the memory and requires loading several scripts, shellcode, and Delphi DLLs until everything is in place for the final payload to be executed inside a Python process, at which point the Python loader chain is completed.
This is completed by instructions.js, which gets the Chrome extensions and installs them on the victim’s computer in the final step. Last but not least, all extensions are started with the appropriate parameters.
As explained by BleepingComputer, the Chaes campaign is still in progress, and people who have been compromised will continue to be in danger long after the websites have been cleaned up.
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Dora is a digital marketing specialist within Heimdal™ Security. She is a content creator at heart - always curious about technology and passionate about finding out everything there is to know about cybersecurity.