January 13, 2023
The Cybereason team has disclosed a recent IcedID malware infection that exemplifies the tactics, techniques, and procedures (TTPs) used in a recent campaign.
IcedID, also known as BokBot, is a banking trojan that steals financial information from its victims. It has been associated with the threat group TA551 since at least 2017. IcedID delivery attacks have used a variety of methods, particularly since Microsoft’s decision to block macros in Office files downloaded from the internet.
The intrusion starts with an ISO image file contained within a ZIP archive and ends with the IcedID payload being executed. It then establishes persistence on the host via a scheduled task and communicates with a remote server to download next-stage payloads, including the Cobalt Strike Beacon for subsequent reconnaissance activity.
It then proceeds to perform lateral movement across the network, executing the same Cobalt Strike Beacon in all of those workstations, before installing the Atera agent, a legitimate remote administration tool, as a redundant remote access mechanism.
Another method is for a Victim to open an archive and then double-click an ISO file, which creates a virtual disk. Following that, the Victim navigates to the virtual disk and selects the only file visible, which is an LNK file. The LNK file executes a batch file that places a DLL in a temporary folder and executes it with rundll32.exe. Meanwhile, Rundll32.exe loads the DLL, which connects to IcedID-related domains and downloads the IcedID payload. The process is then loaded with the IcedID payload.
Other tools used in the attack include a legitimate utility called netscan.exe, which is used to scan the network for lateral movement, and the rclone file syncing software, which is used to exfiltrate directories of interest to the MEGA cloud storage service.
The sources for this piece include an article in TheHackerNews.
