It is unlikely that anyone will argue with the fact that processors are rather complex solutions that simply cannot work without self-diagnostics and sophisticated control tools both at the manufacturing stage and during operation. Developers simply must have the means of "omnipotence" in order to be completely confident in the suitability of the product. And these tools are not going anywhere. In the future, all these diagnostic tools as part of the processor can serve good purposes in the form of remote control technologies such as Intel AMT, and can potentially become a backdoor for special services or intruders, which is often the same for the user.
As you may remember, in May 2016, Positive Technologies specialists discovered that the Intel Management Engine 11 module for implementing AMT technology as part of the system hub (PCH) has undergone major changes and has become vulnerable to malicious attacks. Before version IME 11, the module was on a unique architecture and without special documentation did not pose a particular danger, and it can open access to information in the PC's memory. Since version IME 11, the module has become x86-compatible and available for study by the general public (more on the INTEL-SA-00086 vulnerability here and further on the links). Moreover, a year later, a connection was revealed between the IME and the US NSA surveillance program. Further study of IME led to the discovery of another potential “bookmark” in Intel controllers and processors, which Positive Technologies specialists Maxim Goryachy and Mark Yermolov spoke about yesterday at the Black Hat conference in Singapore.
As part of the PCH hub and in Intel processors, a multifunctional logical signal analyzer VISA (Intel Visualization of Internal Signals Architecture) was found. More precisely, VISA is also an Intel tool for checking processors for serviceability. The documentation for the block is not in the public domain, but this does not mean that it does not exist. The VISA study revealed that the analyzer, initially deactivated at the Intel factory, can be activated by an intruder, and it will provide access to both information in the PC's memory and peripheral signal sequences. Moreover, there were several ways to enable VISA.
We managed to enable VISA and get, for example, access to webcams on a regular motherboard. No special equipment was required for this. Positive Technologies specialists demonstrated this and another example during a report at Black Hat. Nobody connects the presence of VISA directly with the NSA (so far), except, of course, conspiracy theorists. However, if there is an undocumented ability to enable the signal analyzer in any system on the Intel platform, then somewhere it will definitely be enabled.
Source: 3dnews.ru