Malicious user profiles, which have long plagued consumer-oriented social networking sites like MySpace and Facebook, are now appearing on more professionally oriented social networking sites.

Earlier this week, Trend Micro security researcher Ivan Macalintal found several fake LinkedIn profiles that have appropriated the names of celebrities to spread malware.

The scammers use provocative content descriptions in profile name fields -- "Beyoncé Knowles Nude," for example -- to entice visitors to click on malicious URLs placed in the profile's Web site section. Doing so downloads malicious Trojan software.

Other hijacked celebrity names include Victoria Beckham, Christina Ricci, Kirsten Dunst, Salma Hayek, and Kate Hudson.

LinkedIn did not immediately respond to a request for comment.

Trend Micro says that cybercriminals buy and sell preregistered profile accounts on social networks as launchpads for attacks. This happens on other trusted sites and services as well, because exploiting trust is the key to a successful social engineering attack.

A recent social engineering attack that began on Twitter, for example, involved malicious links spammed to Twitter users through the service's direct message system. The links redirected users to a fake Facebook logon page that stole logon credentials from anyone duped by the scheme.

Google has been dealing with similar issues, as demonstrated by the company's designation Tuesday as the third worst spam provider by Spamhaus, an anti-spam group. (Google has since identified and removed the cited spam links and no longer appears on Spamhaus's list.) Spammers have been posting links to malicious Web pages on Google services like Google Docs because potential victims see google.com in the URL and assume the links are trustworthy.