Security News > 2023 > June > Russian hackers use PowerShell USB malware to drop backdoors

Symantec's threat research team, part of Broadcom, reports today that the threat actors have recently begun using USB malware to propagate to additional systems inside infected networks.

Symantec's analysts report that Gamaredon's 2023 activity spiked between February and March 2023, while the hackers continued to maintain a presence on some compromised machines until May 2023.

Symantec sampled 25 variants of PowerShell scripts between January and April 2023, using varying levels of obfuscation and pointing to different Pterodo download IP addresses to resist static detection rules.

Once the victim launches those files, the PowerShell script enumerates all drives on the computer and copies itself to removable USB disks, increasing the likelihood of successful lateral movement within the breached network.

One one of the machines compromised by Gamaredon this year, Symantec's analysts found a "Foto.safe" file that is a base64-encoded PowerShell script.

"These USB drives are likely used by the attackers for lateral movement across victim networks and may be used to help the attackers reach air-gapped machines within targeted organizations," warned Symantec.

News URL

https://www.bleepingcomputer.com/news/security/russian-hackers-use-powershell-usb-malware-to-drop-backdoors/