Twitter | Twitter Acquires Second Security Firm In Three Months

If recent acquisitions are any indication, Twitter is beefing up security on its site.

On Monday, it acquired Dasient, a three-year-old Internet security start-up, marking Twitter's second security acquisition in just three months. Last November, Twitter acquired Whisper Systems, a security service for mobile devices. Terms for both deals were not disclosed.

Twitter, the microblogging service, has long had issues with trending topic scams and spams, and is a frequent target for high-profile hacks. On Monday, as the Dasient acquisition became public, Senator Charles E. Grassley, Republican of Iowa, confirmed that his Twitter account had been hacked . Last month, Lady Gaga told her 18 million Twitter followers that her account had been compromised. And in 2010, the company was the subject of an inquiry by the Federal Trade Commission into its security practices after the Twitter accounts of Facebook, Fox News, President Obama and several other prominent users were hacked.

Dasient's scanning software helps businesses identify and contain malware on the Web. But it also markets what the company calls "the industry's first anti-malvertising service," which claims to protect advertising networks and publishers from malware. The acquisition would seem to complement reports that Twitter is stepping up its monetization efforts with self-service ads .

In a blog post, Dasient said, "By joining Twitter, Dasient will be able to apply its technology and team to the world's largest real-time information network."

Dasient was co-founded in late 2008 by two ex-Googlers, Neil Daswani and Shariq Rizvi, and Ameet Ranadive, formerly of McKinsey Company, with $4 million in seed money from Google Ventures, Floodgate, Radar Partners and Benhamou Global Ventures. In 2010, the company hired Paul Stich, a former vice president at McAfee, as its chief executive.