Malicious QR codes and the persistence of rootkits

Cybercrime has come a long way since it was mostly a digital form of vandalism. It has developed into a criminal business operated for financial gain and is now worth billions. In a new report, AVG focuses on some of the most notable cybercrime developments in the last quarter.

QR codes are becoming popular for mobile users to insert text and URLs into the mobile device without typing. Unfortunately they are also being discovered as an ideal way to distribute malware to unsuspecting victims. The user does not know what lurks behind the QR code until the malware is already installed and running.

Putting a malicious QR code sticker onto existing marketing material or replacing a website’s bona fide QR code with a malicious one could be enough to trick many unsuspecting people.

“In Q4 we clearly saw the convergence between computers and mobile phones applies to malware too. As phones become more like computers, so do the risks,” said Yuval Ben-Itzhak, CTO, AVG Technologies. “Many sophisticated tricks of the trade from computers are now being repurposed for phones. However, as phones are often tied into billing systems the gains can be far greater.”

2011 saw a surge in both Android users and Android malware samples. In December, Google removed another 22 malicious apps from the Android Market, making the total for 2011 pass the 100 mark.

Cyber criminals have now clearly discovered phones as an interesting target. In another sign that mobile phones are becoming more like computers every day, the use of stolen certificates is now making its way to mobile devices.

Digital certificates are often used to certify the identity of the author of an application. If a criminal can get their hands on the certificate belonging to a major software developer, their malware can circumvent security provisions and give users a false sense of security.

Rootkits have been one of the more serious threats to target operating systems in recent years. Rootkits evolved from commercial and financial use to cyber warfare with a very specific target (Stuxnet, Duqu2). Currently we are witnessing the first phase of the rootkit evolution on mobile devices (CarrierIQ3). They are ever evolving to be much more sophisticated with some interesting samples showing up every few months.

In this report we focus on one of the latest rootkits called ZeroAccess, a very sophisticated, very effective rootkit using advanced anti-forensic features. ZeroAccess is a kernel mode rootkit spying on users and is controlled from a remote server. Waiting for commands from the criminals behind it, the rootkit allows the criminals to use the infected machine when and how they wish.

Other key findings in the report:

  • The Blackhole toolkit is currently the most active threat on the web with a share of nearly 50% of all detected instances and over 80% of all toolkits
  • Around a million malicious mobile events have been detected during this quarter
  • The USA is still the largest source of spam, now followed by the UK. Compared to the previous quarter, the UK jumped from fourth to second place overtaking India and Brazil.
  • Brazil is not just a very active banking Trojan market4, the report highlights Portuguese as the second most used language in spam messages.

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