McAfee Stinger does not need installation and can be run from a USB thumbdrive but it asks for administrator rights, this tool has not been designed as a replacement for a fully fledged antivirus, you could use it when you are travelling to check an Internet cafe computer before using it, McAfee Stinger is light on resources, small and fast. After executing it you can select a directory for scanning or scan the whole computer which took me 2 minutes for a 300GB hard drive, McAfee Stinger will scan subdirectories and compressed (.zip,.rar,.7zip) files too, if anything is detected you can choose to repair, rename, delete or report only.
Besides providing protection for travellers using unknown computers this tool can be used as a second opinion if you detect an anomaly, the first thing quality malware will do is to disable your local antivirus, that is why it is important to scan your files with two different antiviruses when something does not add up, as well as checking for outgoing Internet connections.
This tool scans the boot sector which is where rootkits tend to lodge, processes and registry are also scanned, with an heuristic check which sensitivity can be adjusted from Very low to Very high, the default is Medium. Heuristics is a system to detect antivirus like behaviour, meant to discover zero day never seen before threats. McAfee Stinger comes with a very limited list of virus signatures, around 4000, they can be seen by clicking where it says “List of viruses“, it is mostly made up of trojan horses, McAfee claims that it can remove prevalent Fake Alert malware.
If you suspect your computer is infected you might want to check other software that McAfee’s has on its free tools page AntiMalware section, RootkitRemover and GetSusp, both directed at beginners and easy to use, good computer security is made up of layers, the more passive and active security layers you have the less chances of infection, another choice is to use an online antivirus if you are comfortable allowing access to your files.