Der Spiegel has a good article on the NSA's Tailored Access Operations unit: basically, its hackers.
The article also has more details on how QUANTUM -- particularly, QUANTUMINSERT -- works.
Another article discusses the various tools TAO has at its disposal.
A document viewed by SPIEGEL resembling a product catalog reveals that an NSA division called ANT has burrowed its way into nearly all the security architecture made by the major players in the industry -- including American global market leader Cisco and its Chinese competitor Huawei, but also producers of mass-market goods, such as US computer-maker Dell.
In the case of Juniper, the name of this particular digital lock pick is "FEEDTROUGH." This malware burrows into Juniper firewalls and makes it possible to smuggle other NSA programs into mainframe computers. Thanks to FEEDTROUGH, these implants can, by design, even survive "across reboots and software upgrades." In this way, US government spies can secure themselves a permanent presence in computer networks. The catalog states that FEEDTROUGH "has been deployed on many target platforms."
Another program attacks the firmware in hard drives manufactured by Western Digital, Seagate, Maxtor and Samsung, all of which, with the exception of the latter, are American companies. Here, too, it appears the US intelligence agency is compromising the technology and products of American companies.
There is no information in the documents seen by SPIEGEL to suggest that the companies whose products are mentioned in the catalog provided any support to the NSA or even had any knowledge of the intelligence solutions.
The German version of the article had a couple of pages from the 50-page catalog of tools; they're now on Cryptome. This seems to be the whole TOP SECRET catalog; there's a lot of really
interesting information here.
We don't know what "ANT" stands for. Der Spiegel speculates that it "stands for Advanced or Access Network Technology."
Related is this list of NSA attack tools. And here is another article on TAO from October.