(flickr upload by mdornseif)

Sitting down at an unfamiliar (or even a familiar) PC can really risk compromising your personal information. While there are many malicious applications (and even hardware) that don’t readily disclose themselves, there are a few things that should be red flags when using an unfamiliar PC.

• Pop-ups! - If there are pop-up and pop-under windows on the system, beware. Especially beware if they are happening even when the internet browser is not open. The more pop-ups, the more likely the system is significantly compromised.
• Toolbars! - Some toolbars are quite handy and beneficial - Think Google, Yahoo! and Norton Antivirus. If there are other toolbars showing in the browser (especially Internet Explorer), be concerned.
• Internet Explorer! - Though IE7 offers much security improvement over IE6, if Firefox or Opera is installed, use it. Internet Explorer is notoriously vulnerable to attacks and is attacked more often due to its market share.
• Add/Remove Programs - Take a look at the program list in the Add/Remove Programs applet in the Control Panel. There are some malicious or questionable programs that actually list themselves here. User chaslang has a long list of questionable and downright nasty malware over at Major Geeks Forums.
• Windows Updates - If Windows is not current on updates, there could be some problems. In XP’s Control Panel, check to see that “Automatic Updates” is set to automatic.
• Antivirus - Verify that the antivirus definitions are current. Most antivirus programs have an icon in the system tray (next to the clock). Give the icon a double-click and check for the date of the definitions.
• Antispyware - Nowadays all PC’s should be running antispyware. It’s likely accessible in the system tray, too. Check the date of its definitions. If it’s not installed on the PC, beware.

Remember when using PCs that are not yours not to tick any of the “Remember Me” checkboxes when logging into websites. If you believe you’ve logged into a site that’s important (say email or banking) on a PC that may be compromised, change your password for that site ASAP on another (preferably your own) computer. Keep your wits about you when using PCs that are not under your control. If in doubt about a PC’s state of security, move on or be prepared to accept the consequences.