In old good (well, more or less) times, if a victim of cyber attack realised something's wrong, he/she could just call the bank to check if everything's all right and subsequently prevent theft.
But cyber criminals are always evolving. This time they've designed malware to block phone calls to your bank. How? Well, let us tell you, we found a nice article about it.
Android.Fakebank is a malware for Android smartphones (obviously). When it got onto user's device, it tricks the victim into replacing apps of banking institutions that they have installed with fraudulent versions that give the attacker access to the victim's funds.
First the virus was detected by Symantec (company engaged in web security) in October 2013, but this trojan has unfortunately evolved. Now it has nasty functionality of blocking the calls. Meaning, that virus monitors all outgoing calls on the infected device, and if the victim tries to contact his bank, calls to such phone numbers are automatically blocked. Even if you're worried about your account and just want to check things up - you won't be able to call your bank, and the fraudster will have more time.
This virus mostly targets people in South Korea and Russia, and banks in those countries — but such malware could exist elsewhere in the world too. You can protect yourself by only downloading trusted apps from Google Play app store or official website that you know and trust 100% (like adguard.com, for example :))
Because you see, some seemingly secure apps may be advanced viruses in reality.