twitter-target-grayOn Friday, Twitter announced that it had been the target of an attack that compromised approximately 250,000 accounts – but it so far hasn’t said what accounts they were. According to an analysis by Amsterdam-based social analytics company PeerReach, the compromised accounts appear to have included influential journalists, government figures, and tech figures.

According to PeerReach’s sample testing and analysis, there is a “99 percent chance” that the accounts included @barackobama, @nytimes, @reuters, @cnn, and @foxnews, among others. The company outlined its findings in a blog post today. After searching its database for Tweets about people who had to reset their accounts, and asking hundreds of people within its own Twitter networks, PeerReach determined that the hackers compromised a group of accounts that include the Twitter elite. It also consulted independent research that confirmed 50 people who had their accounts hacked. Each user whose account was compromised was sent a note by Twitter telling them to reset their passwords.

PeerReach says its analysis has been confirmed because more than 100 people, including Om Malik, TechMeme founder Gabe Rivera, and Chris Sacca, have indicated on Twitter that their accounts were hacked.

PeerReach did its analysis based on media reports that suggested the only accounts that had been compromised had been started prior to 2007. Twitter has not confirmed any details about the attacks other than to say it was not the work of amateurs and it does not believe it was an isolated incident. “The attackers were extremely sophisticated, and we believe other companies and organizations have also been recently similarly attacked,” Twitter said on Friday.

Within its Politics category, PeerReach estimated, 17 percent of accounts had been affected, including @BarackObama, Slate political reporter John Dickerson (@jdickerson), House Speaker John Boehner (@johnboehner), House Majority leader Eric Cantor (@EricCantor), MSNBC TV host Chris Hayes (@chrislhayes), former US Senator Fred Thompson (@fredthompson), RedState.com editor Erick Erickson (@EWErickson), Vice President Joe Biden (@JoeBiden), CNN reporter Peter Hamby (@PeterHambyCNN), and Republican tech strategist Patrick Ruffini (@PatrickRuffini).

From PeerReach’s WebTech top 100, 70 percent of accounts had been targeted, including @TechCrunch, Evan Williams (@ev), Tim O’Reilly (@timoreilly), Fred Wilson (@fredwilson), Om Malik (@om), Kara Swisher (@karaswisher), Jack Dorsey (@jack), Chris Sacca (@sacca), Biz Stone (@biz), and Kevin Rose (@kevinrose).

PeerReach also found that 22 percent of the most influential journalist and media accounts were affected. They included @nytimes, @Reuters, @BreakingNews, @CNN, @nprnews, @Newsweek, @BBCBreaking, @nickbilton, @BBCWorld, and @guardiannews.

Twitter has written on its blog that its investigation has indicated that attackers may have had access to limited user information, including usernames, email addresses, session tokens, and encrypted versions of passwords.

The attacks were revealed after reports that the New York Times, the Wall Street Journal, and the Washington Post had been victims of attacks by Chinese hackers.

We have reached out to Twitter for comment and will update this story as it develops.