Before you go around scanning QR codes with your mobile device willy-nilly, you should read through AVG's threat report for Q4 2011. In it AVG provides insight and analysis on trending security threats, and highlights in this latest installment include risks of QR codes, stolen digital certificates bypassing security on mobile phones, and the persistence of rootkits.
According to AVG, the growing popularity of QR codes is attracting the attention of malware writers looking for quick and easy targets.
"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," AVG warns .
AVG said it detected around a million malicious mobile events during the fourth quarter of 2011, more than three-quarters (78 percent) of which were distributed via rooting tools. Traditional malware accounted for 14 percent, and hacking tools rounded things out by accounting for 8 percent of mobile threats.
You can read the full report here (PDF) .