image
A previously undocumented modular loader has emerged as a lucrative tool for cybercriminals in a variety of campaigns. Researchers say the “highly competitive” loader, dubbed Buer, is intended for use by actors seeking a turn-key, off-the-shelf solution. Researchers say they have spotted the loader being actively sold in prominent underground marketplaces since August 2019. Consequently, Buer has made an appearance in several malicious email campaigns and via exploit kits, to then download various strains of malware – from the TrickBot banking trojan to the KPOT information stealer. “The new loader has robust geotargeting, system profiling and anti-analysis features and is currently being marketed on underground forums with value-added setup services,” said researchers with Proofpoint on Wednesday. Buer in the Wild Researchers first came across Buer in the wild in a slew of malicious August email messages, purporting to be replies to earlier legitimate email messages. The emails contained Microsoft Word attachments that used macros to download a next-stage payload. Upon further analysis, researchers found the naming convention for this payload (verinstere222.xls or verinstere33.exe), was frequently associated with the Dreambot variant of Ursnif. However, they were surprised to find that the payload instead droppe Buer, an undocumented loader not previously observed in the wild. “In the following weeks over September and October, Proofpoint researchers and other members of…

Source