Yahoo! owned RightMedia has been serving ads to popular networks such as MySpace, Bebo and Photobucket that could wreak havoc on visitors' machines.

The Trojan which was reported to have been inserted by a third party ad server, was tracked down to RightMedia. The infected banner ad supposedly ran several million times over a three week period after it was first spotted on August 8th by a web security company before it was removed.

The ads used Flash to load an invisible iFrame which in turn would load content in from another website. RightMedia has said that it has systems in place to test and determine whether ads contain malicious code, and will flag them appropriately. Upon further investigation of the ad, code inserted was actually designed to tell the difference between RightMedia's protection systems and not display the Trojan when the company ran the testing process.

All we can say is, "Hello Firefox with AdBlock!"

When Google goes and buys DoubleClick and Yahoo! responds by purchasing Right Media, what does that leave for companies like AOL? How about behavioral-targetting ad firm TACODA?

Today AOL (this blog's parent company) announced that it has entered into an agreement to acquire TACODA. AOL plans to use TACODA's targeted advertising technology to extend its own ad network. TACODA currently serves up ads for about 4,000 websites reaching over 125 million users.

Terms of the deal haven't been disclosed, but the New York Post reports that AOL could be paying from $200 to $300 million for TACODA.

In October Yahoo! picked up a 20% stake in advertising company Right Media. Today, Yahoo! bought the other 80% for $680 million in cash and stock.

This comes just weeks after Google picked up advertising giant DoubleClick for $3.1 billion. In other words, the big search portals ain't just about searching no more. Okay, that's been true for a while, but this makes Google and Yahoo! two of the biggest names in online advertising.

Right Media runs an advertising marketplace, or an exchange where advertisers and publishers can buy and sell online ads through auctions. Yahoo! had been using Right Media to place ads on its own sites since last year.

DoubleClick plans its own advertising marketplace, but has yet to do so.