The attack was reportedly carried out by unknown hackers in the past few days.
"Al-Qaeda's online communications have been temporarily crippled, and it does not have a single trusted distribution channel available on the Internet," Evan Kohlmann of Flashpoint Global Partners, which monitors the outfit's communication, was quoted as saying by the NBC News.
It was "well coordinated and involved the use of an unusual cocktail of relatively sophisticated techniques," Kohlmann said.
"My guess is that it will take them at least several days more to repair the damage and get their network up and functioning again," he said.
British newspapers reported earlier this month that the UK government had also hacked into al-Qaeda's online magazine - Inspire - and replaced instructions to make bombs with instructions to make cupcakes.It reportedly took the terrorist organization two weeks to get back the original posting.
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