Security software firm Webroot has pinpointed the most common forms of malicious security threats in the UK, picking out the Trojan Downloader Zlob as the biggest offender (see the PC Advisor forums for more on Zlob).

Webroot said some variants of the Trojan, which disguises itself as a harmless program and is generally distributed as an email attachment, allow hackers to remotely control and use infected computers for malicious purposes. The security firm said Zlob often installs bogus security programs such as SpywareQuake, SpyFalcon, SpyLocked and WinAntivirusPro, in addition to other malware.

180search Assistant/Zango was identified as being the most widespread adware, followed closely by Hotbar/Zango and Starware Toolbar, which Webroot describes as an “extremely high-level threat” that's capable of tracking a users' internet surfing habits and delivering information to a third party.

Keyloggers also remain a concern for UK computer users, with Webroot picking out Perfect Keylogger as the most regular System Monitor. Such tools can monitor key strokes, emails, chat room conversations, instant messaging, websites visited, usernames and passwords.