The company had sent another email to subscribers earlier in the day saying it had suspended its servers and email after learning that its website had been hacked.
One member of the hacking group, who uses the handle AnonymousAbu on Twitter, claimed that more than 90,000 credit cards from law enforcement, the intelligence community and journalists -- "corporate/exec accounts of people like Fox" News -- had been hacked and used to "steal a million dollars" and make donations.
It was impossible to verify where credit card details were used. Fox News was not on the excerpted list of Stratfor members posted online, but other media organizations including MSNBC and Al-Jazeera English appeared in the file.
Anonymous warned it has "enough targets lined up to extend the fun fun fun of LulzXmas through the entire next week."
The group has previously claimed responsibility for attacks on credit card companies Visa Inc. and MasterCard Inc., eBay Inc.'s PayPal, as well as other groups in the music industry and the Church of Scientology.