Excerpt:
"The first $2 million was delivered shortly before that letter was written. In it, Mr. Rahman asked Bin Laden if he needed money, and said “we have also designated a fair amount to strengthen the organization militarily by stockpiling good weapons.” (The Qaeda leaders named in the letters were identified by aliases. Bin Laden, for instance, signed his letters Zamray; Mr. Rahman, who was killed in a drone strike in Pakistan in August 2011, went by the alias Mahmud.)"
http://www.nytimes.com/2015/03/15/world/asia/cia-funds-found-their-way-into-al-qaeda-coffers.html?_r=1