The Anti-virus Times

Wednesday, November 2, 2016

A botnet is a cluster of malware-infected computing systems that are remotely managed by cybercriminals to perform various illegal activities.

Usually, botnets consist of infected computers, but virus writers are increasingly trying to form them by infecting mobile devices.

Currently, Android-powered smartphones and tablets are at risk of becoming part of a botnet.

Once cybercriminals get control over mobile devices, they can "command" them to carry out any action.

The most popular malicious functions of mobile botnets are:

• sending spam;
• stealing confidential information;
• engaging in cyberespionage;
• displaying unwanted advertisements;
• performing DDoS attacks on websites.

In some cases, "mobile" botnets consist of tens of thousands of infected devices.

A striking example is Android.SmsBot.120.origin. It was detected in June 2014 by Dr.Web specialists on more than 670,000 devices. This malware could send, intercept, and delete SMS; load specified webpages into browsers; obtain device coordinates; and even remove specific applications!

"Mobile" botnets formed from Android-powered handhelds and infected by banking Trojans are becoming more and more common.

Take, for instance, Android.Wormle.1.origin, the banking Trojan that was introduced in November 2014. It could perform multiple actions and managed to infect more than 15,000 handhelds in many countries. Cybercriminals could command the Trojan not only to covertly transfer money from a victim's credit card, but also to perform a variety of other harmful tasks:

• send SMS;
• delete installed programs and files;
• steal a variety of confidential information;
• and even carry out DDoS attacks on websites.

Since the end of 2015, attackers have used different modifications of Android.SmsSpy.88.origin to form dozens of botnets (encompassing over 40,000 devices). This malware was designed to steal user online banking login credentials and bank card data. In addition, the Trojan can also steal all SMS messages, send spam to all the contacts found in a device’s phone book, and even lock the screens of infected devices, forcing users to pay to have their devices unlocked.