Newly SLEEPWALKER Backdoor Waits for One Crafted Packet, Then Runs Its Own Bytecode

SLEEPWALKER exploits DLL side-loading by masquerading as a legitimate library within ESET Management Agent, allowing it to persist undetected in memory until a single crafted network packet activates it. Its custom 23-instruction bytecode language bypasses signature-based detection tools that rely on known malware patterns. This attack highlights the danger of trusting processes solely because they appear to originate from legitimate software. The ability to remain dormant and blend into trusted agent traffic makes it particularly stealthy against traditional network monitoring. Organizations that lack deep application integrity verification and robust network behavioral analysis are especially vulnerable to this class of threat.