A new banking malware is pushed on Android devices, and
it’s using source code from the older, now defunct, Xerxes, and an even older
variant called LokiBot. The attackers target apps that haven’t been compromised
in other campaigns.
Banking trojans are always evolving along with the
operating systems they are trying to infect. Since they are usually spotted in
apps before being distributed through official stores, criminals choose other
channels, such as unofficial stores and shady websites offering third-party
files.
When new Android versions are released, the older malware
doesn’t work, so new versions appear, usually based on older code. The
BlackRock variant is only the latest one, but its foundations use code from
malware that appeared over the past four years.
ThreatFabric looked at how the new BlackRock malware acts
once it infects a device. As expected, once it gets a hold of a device, all information
can be compromised.
“When the malware is first launched on the device,
it will start by hiding its icon from the app drawer, making it invisible to
the end-user,” say
the researchers. “As second step it asks the victim for the Accessibility
Service privileges. As visible in following screenshot, the Trojan’s largest
campaigns are posing as fake Google updates.”
The Accessibility Service on Android has an entirely
different purpose, but it’s powerful and often exploited by malware operators
to gain the necessary right.
Commands supported by BlackRock include the option to
send an SMS, to send SMS copies of personal emails to control and command
centers, to start apps on boot, to force devices to stay on the HOME screen, to
add a managed admin profile for the malware on the device, and much more.
Since this is a banking trojan, it will try to steal
credit card credentials, either with a grabber view or with a phishing overlay
specific to each app. The malware steers the user to local files as opposed to
the web version, after which the details are uploaded to the C&C center.
Many apps targeted by the malware are not financial, but
social media, communication, or dating apps. It’s just one of the many ways to
steal credentials that can be used in other situations.
As for the targets themselves, the malware is directed at
European banks and users, followed by those in Australia, the US and Canada.
People should only use official distribution channels for
their Android apps and have an endpoint security solution installed at all
times.