A US based advertising firm has promised to stop bombarding Facebook users with fraudulent messages in exchange for Washington State officials dropping a lawsuit that claimed the practice violated a federal antispam statute.

Adscend Media also agreed to pay $100,000 in attorneys' fees to settle charges Washington state's attorney general brought in January claiming the misleading messages violated a federal law known as the CAN-SPAM, short for Controlling the Assault of Non-Solicited Pornography and Marketing. The settlement also requires Adscend Media to regularly monitor its affiliate partners to make sure they're in compliance as well.

According to documents filed in US District Court in Seattle (PDF), Adscend Media used a proprietary network of affiliates to target Facebook users with unsolicited messages that had been manipulated to appear as if they originated from friends. Carrying headlines such as "OMG! See What Happens to his Ex Girlfriend" the bait pages required users to click buttons that masqueraded as age verification checks from Facebook but really caused the messages to get posted on users' Facebook News Feeds to allow them to spread virally.

The messages never disclosed that they originated with Adscend Media for purposes of driving traffic to the websites of its customers, Washington officials alleged. The company had gross monthly revenue of about $1.2 million, and 80 percent of its income was derived from Facebook solicitations. Facebook recently settled a civil lawsuit with Adscend Media over the same practice. Adscend Media didn't admit any wrongdoing in Monday's settlement.

Security researchers have dubbed attacks that cause Facebook users to unwittingly endorse websites and products "Likejacking."

Update

After this post was published, an Adscend Media representative emailed a statement that said the settlement was reached after Washington State officials dropped two thirds of the legal claims they originally brought against the company. "The State apparently lost confidence in its case and wanted to quickly bring an end to it," Mark J. Rosenberg, an attorney representing Adscend Media, said. "Our contention from the outset was that this case had no merit, and we believe the outcome validates our position."

Story updated on May 11 to add comment from Adscend Media.