Security company ESET, the creator of the well-known NOD32 antivirus, published the "Global Threat Trend - March 2008" report, underlining, once again, that our USB sticks are in danger due to the popularity of INF/Autorun. Thus, no less than 10.3 percent of the total number of threats discovered in March 2008 was represented by INF/Autorun, the infection which usually attacks removable drives.

"During the month of March 2008, close to 10.30% of all threat detections were flagged as INF/Autorun. This detection label is used to describe a variety of malware that tries to use the file autorun.inf as a way of compromising a PC. This file contains information on programs to be run automatically when removable media (often USB memory sticks) are inserted into a computer, and ESET NOD32 identifies malware that installs or modifies autorun.inf files as INF/Autorun," ESET wrote in the report.

For those of you who don't know, the removable drives infections usually propagate through USB flash drives which are compromised once they are plugged into an infected system. Just after the stick is connected to the "damaged" computer, the infection is automatically copied on the clean disc and waits until it's plugged into a clean system. This way, it propagates on both USB flash drives and clean computers.

The second place, with no less than 4.42 percent of the total number of threats, goes to Win32/Adware.SearchAid, an infection which "used to direct a browser to pop-up ads, and is installed as part of the licensing requirements of another application," according to ESET.

As you can see, extra-care when working with USB flash drives is always welcome, as well as an up-to-date antivirus, firewall and other security solution that you may have installed on your computer.