Italian corporate banking clients have been the targets of an ongoing financial fraud campaign, according to cybersecurity firm Cleafy. The campaign has been using a web-inject toolkit called drIBAN since at least 2019. The main goal of the campaign is to infect Windows workstations inside corporate environments to alter legitimate banking transfers and transfer money to an illegitimate bank account controlled by the threat actors or their affiliates.
The fraudulent transactions are often realized by means of a technique called Automated Transfer System (ATS) that is capable of bypassing anti-fraud systems put in place by banks and initiating unauthorized wire transfers from a victim’s own computer.
The attack chain begins with a certified email in an attempt to lure victims into a false sense of security. These phishing emails come with an executable file that acts as a downloader for a malware called sLoad (aka Starslord loader).
sLoad is a reconnaissance tool that collects and exfiltrates information from the compromised host, with the purpose of assessing the target and dropping a more significant payload like Ramnit if the target is deemed profitable. sLoad also leverages living-off-the-land (LotL) techniques by abusing legitimate Windows tools like PowerShell and BITSAdmin as part of its evasion mechanisms.
Another characteristic of the malware is its ability to check against a predefined list of corporate banking institutions to determine if the hacked workstation is one among the targets, and if so, proceed with the infection. “All the bots that successfully pass those steps will be selected by botnet operators and considered as ‘new candidates’ for banking fraud operations moving forward to the next stage, where Ramnit, one of the most advanced banking trojans, will be installed,” the researchers said.
The operators behind drIBAN have gotten savvier at avoiding detection and developing effective social engineering strategies, in addition to establishing a foothold for long periods in corporate bank networks.
Cleafy said 2021 was the year when the classic “banking trojan” operation evolved into an advanced persistent threat. There are also indications that the activity cluster overlaps with a 2018 campaign mounted by an actor tracked by Proofpoint as TA554 targeting users in Canada, Italy, and the UK.
The use of web injects is a time-tested tactic that makes it possible for malware to inject custom scripts on the client side by means of a man-in-the-browser (MitB) attack and intercept traffic to and from the server.
