March 9, 2017 By Larry Loeb 2 min read

Software Guard Extensions (SGX) are essentially an isolation mechanism. Like an RSA key, it tries to protect code and data from modification or disclosure, even if all privileged software is considered malicious.

Now, Intel added the SGX to its hardware starting with Skylake models in an effort to get a protective fence nailed down around data as it floats through the cloud.

The SGX Concept

The idea was that if you stored the keys inside this special enclave memory area, it would be encrypted and kept isolated from the rest of the chip through Intel’s hardware. Even if attackers got into the enclave somehow, they would find data encrypted and useless — or so Intel thought.

But five people at Graz University of Technology in Austria came up with a way to hose SGX. They devised an attack method that utilizes the first known SGX malware, which they also developed.

These researchers wrote a paper, titled “Malware Guard Extension: Using SGX to Conceal Cache Attacks,” that gets into the details of how they operate the malware. To make their point, they showed it working both in a native environment and across multiple Docker cloud containers.

The malware was a key-stealing proof of concept (PoC) that was directed at another co-located, secured enclave. The malware used SGX against itself, keeping its existence secret from other software processes by hiding inside of the SGX isolation.

Recovering the RSA Key

The researchers reported that the PoC malware was able to recover RSA keys by monitoring the cache access patterns of an RSA signature process in a semisynchronous attack. They found that a “Prime+Probe cache side-channel” attack could get 96 percent of an RSA private key from just one single trace, according to the paper.

SecurityWeek noted that the attack could extract the full RSA private key from 11 traces within five minutes of operation. Once the attackers have the private key, the enclave can be decrypted.

Researchers were able to come up with “highly accurate” timings within an enclave without access to the native time stamp counter. In fact, they reported that the method they used to replace the timer is even more accurate than if they had access to the native counter.

There is no easy mitigation for this problem. A comprehensive solution may require changes to the enclave, operating system and hardware itself. Until a resolution is found, this is a serious and ubiquitous vulnerability, and SGX is making it undetectable.

More from

Generative AI security requires a solid framework

4 min read - How many companies intentionally refuse to use AI to get their work done faster and more efficiently? Probably none: the advantages of AI are too great to deny.The benefits AI models offer to organizations are undeniable, especially for optimizing critical operations and outputs. However, generative AI also comes with risk. According to the IBM Institute for Business Value, 96% of executives say adopting generative AI makes a security breach likely in their organization within the next three years.CISA Director Jen…

Q&A with Valentina Palmiotti, aka chompie

4 min read - The Pwn2Own computer hacking contest has been around since 2007, and during that time, there has never been a female to score a full win — until now.This milestone was reached at Pwn2Own 2024 in Vancouver, where two women, Valentina Palmiotti and Emma Kirkpatrick, each secured full wins by exploiting kernel vulnerabilities in Microsoft Windows 11. Prior to this year, only Amy Burnett and Alisa Esage had competed in the contest's 17-year history, with Esage achieving a partial win in…

Self-replicating Morris II worm targets AI email assistants

4 min read - The proliferation of generative artificial intelligence (gen AI) email assistants such as OpenAI’s GPT-3 and Google’s Smart Compose has revolutionized communication workflows. Unfortunately, it has also introduced novel attack vectors for cyber criminals. Leveraging recent advancements in AI and natural language processing, malicious actors can exploit vulnerabilities in gen AI systems to orchestrate sophisticated cyberattacks with far-reaching consequences. Recent studies have uncovered the insidious capabilities of self-replicating malware, exemplified by the “Morris II” strain created by researchers. How the Morris…

Topic updates

Get email updates and stay ahead of the latest threats to the security landscape, thought leadership and research.
Subscribe today