Monday, 29 August 2016

First Twitter-controlled Android botnet discovered

ESET researchers discovered an Android backdoor Trojan controlled by tweets. Detected by ESET as Android/Twitoor, it’s the first malicious app using Twitter instead of a traditional command-and-control (C&C) server.

ESET researchers discovered an Android backdoor Trojan controlled by tweets. Detected by ESET as Android/Twitoor, it’s the first malicious app using Twitter instead of a traditional command-and-control (C&C) server.

Android/Twitoor has been active since July, 2016. It can’t be found on any official Android app store – according to Stefanko - but probably spreads by SMS or via malicious URLs. It impersonates a porn player app or MMS application but without the functionality. Instead, it has been downloading several versions of mobile banking malware. However, the botnet operators can start distributing other malware at any time, including ransomware.

After launch, the Trojan hides its presence on the system and checks the defined Twitter account in regular intervals for commands. Based on received commands, it can either download malicious apps or change the C&C Twitter account to another one.

“Using Twitter to control a botnet is an innovative step for an Android platform,” says Lukas Stefanko, the ESET malware researcher who discovered the malicious app. Communication channels based on social networks are hard to discover and impossible to block entirely – while simultaneously being extremely easy for the crooks to re-direct communications to another account.

Twitter was first used to control Windows botnets in 2009. “As for the Android space, this means of hiding has remained untapped until now. In the future, however, we can expect that the bad guys will try to make use of Facebook statuses or deploy LinkedIn and other social networks”, envisages Stefanko.