US Patent 9251343 Detecting bootkits resident on compromised computers

Techniques detect bootkits resident on a computer by detecting a change or attempted change to contents of boot locations (e.g., the master boot record) of persistent storage, which may evidence a resident bootkit. Some embodiments may monitor computer operations seeking to change the content of boot locations of persistent storage, where the monitored operations may include API calls performing, for example, WRITE, READ or APPEND operations with respect to the contents of the boot locations. Other embodiments may generate a baseline hash of the contents of the boot locations at a first point of time and a hash snapshot of the boot locations at a second point of time, and compare the baseline hash and hash snapshot where any difference between the two hash values constitutes evidence of a resident bootkit.