The Marcher Android banking trojan received a significant update last month and is now capable of targeting UK banks, along with its usual list that has until now included banks from Germany, Austria, France, Australia, Turkey, and a few other more.
To better understand why the trojan is now extremely dangerous and why UK users should be very wary of what they install on their phones, a short lesson in Marcher history is needed.
Marcher evolved from credit card data stealer to full mobile banking trojan. The malware first appeared in late 2013, and in the beginning, it was only able to show overlays on top of the user's Google Play app, asking them to enter their credit card details. As time went by, the trojan evolved and began targeting banking apps, showing the same overlay, but tweaked to collect banking credentials. At first, it was one large German bank, but the list kept growing to include countries all over the world.
Marcher can also intercept and redirect calls and SMS messages, a function that's useful for bypassing a bank's 2FA system. Additionally, these features are also used to place calls or SMS messages to premium numbers, allowing the crook to make some extra cash on the side.
The crooks didn't miss any chance to monetize their threat, and the trojan also received updates in order to target all sorts of social networking and mobile payment apps, not just banks.
Marcher sold on the underground malware market
IBM says the trojan is most likely developed by a Russian-speaking developer, who sells it via Russian underground cyber-crime forums, either directly or through intermediaries. Despite all these features that allow it to phish for banking credentials, the security firm claims that there's been a period of calm in terms of bank credentials phishing. Things changed in May, when Marcher's developer added support for nine big UK banks and returned to banking apps credentials phishing.
Furthermore, the trojan is now also capable of showing phishing overlays inside mobile browsers, similarly to how desktop banking trojans work. Previously, Marcher only showed fullscreen overlays that covered the user's entire phone display.
Marcher can now detect and bypass mobile AV solutions
To counteract the proliferation of mobile antivirus solutions, which are becoming the norm on mobile devices, the trojan now also comes hardcoded with support to evade at least eight mobile antivirus apps.
The current Marcher distribution and infection campaign relies on SMS and email spam that lures users into downloading a fake Adobe Flash Player for their mobile device. Users should avoid installing apps from outside the Google Play Store as well as giving any app administrator privileges unless it's for a well-known and trusted source.