During the past years, we've seen rapid increase in worms spreading via removable drives; either by using various features of the operating system or simply by tricking users into running the malware. As the time went by, the number of users on our malware removal forum that came back infected after a day or two, kept increasing. In most cases, the source of reinfection was an infected removable drive (a USB pen drive, digital camera, mobile phone...). The users also realized that there's a weak point in their computer's security and kept asking questions and recommendations for a good "USB antivirus", but we just couldn't give them one - we considered them either worthless or overpriced. Some time in the late 2009. an idea of a tool that could help was born. The tool, MCShield, has been designed as a lightweight scanner that's smart enough to catch even new worms and work in fully automatic removal mode. It won't slow down the PC and it's simple enough even for a novice user. It's freeware.