Android trojan posing as government services and Starlink apps

[harlan4096]

We break down the BeatBanker trojan attack, which combines espionage, crypto theft, and mining with inventive ways to dig its heels into a smartphone.
 
To achieve their malign aims, Android malware developers have to address several challenges in a row: trick users to get inside their smartphones, dodge security software, talk victims into granting various system permissions, keep away from built-in battery optimizers that kill resource hogs, and, after all that, make sure their malware actually turns a profit. The creators of the BeatBanker — an Android‑based malware campaign recently discovered by our experts — have come up with something new for each one of these steps. The attack is (for now) aimed at Brazilian users, but the developers’ ambitions will almost certainly push them toward international expansion, so it’s worth staying on guard and studying the threat actor’s tricks. You can find a full technical analysis of the malware on Securelist.

How BeatBanker infiltrates a smartphone

The malware is distributed through specially crafted phishing pages that mimic the Google Play Store. A page that’s easily mistaken for the official app marketplace invites users to download a seemingly useful app. In one campaign, the trojan disguised itself as the Brazilian government services app, INSS Reembolso; in another, it posed as the Starlink app.



The malicious site cupomgratisfood{.}shop does an excellent job imitating an app store. It’s just unclear why the fake INSS Reembolso appears all of three times. To be extra sure, perhaps?!

The installation takes place in several stages to avoid requesting too many permissions at once and to further lull the victim’s vigilance. After the first app is downloaded and launched, it displays an interface that also resembles Google Play and simulates an update for the decoy app — requesting the user’s permission to install apps, which doesn’t look out-of-the-ordinary in context. If you grant this permission, the malware downloads additional malicious modules to your smartphone.



After installation, the trojan simulates a decoy app update via Google Play by requesting permission to install applications while downloading additional malicious modules in the process

All components of the trojan are encrypted. Before decrypting and proceeding to the next stages of infection, it checks to ensure it’s on a real smartphone and in the target country. BeatBanker immediately terminates its own process if it finds any discrepancies or detects that it’s running in emulated or analysis environments. This complicates dynamic analysis of the malware. Incidentally, the fake update downloader injects modules directly into RAM to avoid creating files on the smartphone that would be visible to security software.

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