Biblio

Anti-virus software (AVS) tools are used to detect Malware in a system. However, software-based AVS are vulnerable to attacks. A malicious entity can exploit these vulnerabilities to subvert the AVS. Recently, hardware components such as Hardware Performance Counters (HPC) have been used for Malware detection. In this paper, we propose PREEMPT, a zero overhead, high-accuracy and low-latency technique to detect Malware by re-purposing the embedded trace buffer (ETB), a debug hardware component available in most modern processors. The ETB is used for post-silicon validation and debug and allows us to control and monitor the internal activities of a chip, beyond what is provided by the Input/Output pins. PREEMPT combines these hardware-level observations with machine learning-based classifiers to preempt Malware before it can cause damage. There are many benefits of re-using the ETB for Malware detection. It is difficult to hack into hardware compared to software, and hence, PREEMPT is more robust against attacks than AVS. PREEMPT does not incur performance penalties. Finally, PREEMPT has a high True Positive value of 94% and maintains a low False Positive value of 2%.

The wide deployment of general purpose and embedded microprocessors has emphasized the need for defenses against cyber-attacks. Due to the globalized supply chain, however, there are several stages where a processor can be maliciously modified. The most promising stage, and the hardest during which to inject the hardware trojan, is the fabrication stage. As modern microprocessor chips are characterized by very dense, billion-transistor designs, such attacks must be very carefully crafted. In this paper, we demonstrate zero overhead malicious modifications on both high-performance and embedded microprocessors. These hardware trojans enable privilege escalation through execution of an instruction stream that excites the necessary conditions to make the modification appear. The minimal footprint, however, comes at the cost of a small window of attack opportunities. Experimental results show that malicious users can gain escalated privileges within a few million clock cycles. In addition, no system crashes were reported during normal operation, rendering the modifications transparent to the end user.