Bytecode Attackers Can Hide Malicious Code in Memory: Researchers Demonstrate at Black Hat USA

Researchers from Japan are set to unveil a groundbreaking technique at the upcoming Black Hat USA conference that allows attackers to hide their malicious code within the bytecode stored in memory by popular software interpreters. By inserting commands into the bytecode used by languages like VBScript and Python, attackers can evade detection by security software, making it difficult for endpoint protection systems to identify the threat.

The research team, comprised of experts from NTT Security Holdings Corp. and the University of Tokyo, successfully demonstrated how malicious instructions can be seamlessly integrated into the bytecode before execution. This method capitalizes on the fact that security software typically overlooks bytecode, creating a blind spot that attackers can exploit to conceal their activities.

Known as Bytecode Jiu-Jitsu, this novel attack technique leverages the inherent nature of interpreters to execute bytecode without requiring special privileges. By infiltrating the running interpreter’s memory space with malicious bytecode, attackers can avoid more conspicuous actions that would typically raise red flags for security tools.

While traditional defenses like pointer checksums may not be effective against these bytecode attacks, developers have the opportunity to enhance interpreter security by implementing write protections to restrict memory writes. The ultimate goal of showcasing this technique is to raise awareness among security researchers and defenders, prompting proactive measures to combat evolving threats in the digital landscape.