A new variant of the Ursnif trojan has been discovered targeting Japan since the beginning of 2019. Japan is a common target for Ursnif, but the latest version, delivered by Bebloh, goes to increased lengths to ensure that the victim is indeed Japanese.
New variants of Ursnif are not uncommon since the source code was leaked in 2015, but this version also includes enhanced data theft modules for stealing data from mail clients and email credentials stored in browsers. Other new developments, according to Cybereason research, include a new stealthy persistence module, a cryptocurrency and disk encryption module, and an anti-PhishWall (a Japanese security product) module.
This version of Ursnif also adds some anti-security product capabilities aimed at defeating PhishWall and Rapport. PhishWall is a popular Japanese anti-phishing and anti-banking trojan application, and anti-PhishWall modules have been used by other trojans in the past (such as Shifu and Bebloh).
The anti-Rapport module is designed to defeat IBM Trusteer’s Rapport product. This is not new, but not often seen in malware targeting Japan. The code seems to be based on — if not copy/pasted from — Carberp’s anti-Rapport code (which is freely available on GitHub). Cybereason notes that it has tested neither the PhishWall nor the Rapport module, so cannot attest to their efficiency.
Cybereason is unsurprised by the new concentration on data stealing highlighted by the new version of Ursnif. “With more and more banking customers shifting to mobile banking and the continuous hardening of financial systems,” writes the researcher, “it is not surprising that trojans are beginning to focus more than ever before on harvesting non-financial data that can also be monetized and exploited by the threat actors.”
But what stands out from this campaign, he adds, “is the great effort made by threat actors to target Japanese users. They use multiple checks to verify that the targeted users are Japanese, as opposed to other more prolific trojans and information stealers that cast a wider net when it comes to their victims.”
New Variant of Ursnif Targeting Japan by Kevin Townsend: