Researchers are warning that usernames, passwords and other credentials of online banking users in Japan may be compromised thanks to a Trojan that builds off of previous vulnerabilities in Adobe Flash Player and Microsoft’s Internet Explorer (IE).

An alert from ESET, which provides online scanning tools, offered details on Brolux, a Trojan that cybercriminals are using to track online banking activity by monitoring the URLs consumers visit. Brolux works by installing a pair of configuration files that contain both URLs that can be cross-referenced and popular Japanese financial services firms’ window titles. If cybercriminals see an opportunity, potential victims are directed to a page that resembles the country’s Financial Services Agency or the Japanese Public Prosecutor’s Office.

As SecurityWeek pointed out, this is just the latest instance of malware creators targeting Japanese online banking users. Although the degree of organized cybercrime in the country is believed to be in its early stages, according to a study from Trend Micro, similar threats hitting customers of financial institutions include malware such as Neverquest, Tsukuba and Shifu.

One of the interesting aspects of Brolux is its use of previously reported bugs in Flash Player and the so-called Unicorn vulnerability in IE. We Live Security compared the malware’s distribution method through an adult website to Win32/Aibatook, which also focused on Japanese online banking customers. In this case, however, the site luring potential victims is aggregating pornographic images and videos from other sites.

Hopefully, anyone who hasn’t already updated or patched Flash Player and IE will do so as news of Brolux spreads. In the meantime, expect many similar threats to emerge as cybercriminals simply modify or tweak previous vulnerabilities and exploits to distribute malware. Shifu, for example, made use of the widely known Angler exploit kit to go after online banking users in the U.K. Other features in Shifu were also reportedly copied from previous Trojans.

In other words, cybercriminals are making no attempt to be original here; they’re simply being as persistent as possible in the hopes of gaining control of more personal information over time.