A Silent Threat Hiding in Archive Extraction
A critical zero-day vulnerability in WinRAR (CVE-2025-8088) was recently discovered and actively exploited in the wild. Attackers linked to the Russia-aligned group RomCom (also known as Storm-0978, Tropical Scorpius, UNC2596) weaponized archive extraction to stealthily implant malware. (BleepingComputer)
Researchers at ESET found that RomCom distributed malicious .rar files through spear-phishing campaigns, often disguised as job applications. Once extracted, the archives dropped payloads like SnipBot, RustyClaw, and Mythic Agent into Windows autorun directories, creating persistence and granting attackers a foothold.
WinRAR released a patch in version 7.13 to address the flaw, but since the tool does not auto-update, many users remained exposed for weeks after the fix was available.
Why Detect and Respond Is Not Enough
Many organizations still rely heavily on a Detect and Respond approach: spotting attacks after they begin and then reacting. With exploits like this one, even advanced detection struggles to catch malware when it hides in trusted folders or mimics normal system behavior. By the time suspicious activity is flagged, attackers may already have persistence, lateral movement, or data exfiltration underway.
RomCom's use of weaponized archives demonstrates how easy it is for adversaries to bypass detection. The lure looks legitimate, the extraction process feels routine, and the payload blends into system files. Detecting after the fact is often too late.
The Power of Isolation and Containment
An Isolation and Containment approach changes the equation. Instead of waiting to detect bad behavior, it prevents unauthorized execution outright:
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Containment of executable behavior: AppGuard blocks unknown or suspicious binaries from running, even when hidden in autorun folders.
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Isolation of risky processes: If a program like WinRAR is exploited, any malicious file extracted cannot escape the isolated zone.
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Prevention first: Malware is stopped before it can establish persistence or carry out harmful actions.
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Operational continuity: Legitimate business processes continue uninterrupted while malicious activity is neutralized.
AppGuard: Proven Endpoint Protection
AppGuard uses a prevention-first approach with over 10 years of success in protecting sensitive environments. Unlike tools that only detect and respond, AppGuard enforces strict execution controls at the kernel level.
In the case of this WinRAR exploit, AppGuard would:
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Prevent unauthorized changes to autorun folders and registry entries.
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Block new executables dropped from the archive from ever launching.
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Contain malware immediately, preventing it from spreading or persisting.
The Time to Act Is Now
The WinRAR incident highlights a hard truth: traditional detection is no longer enough. Attackers continue to use simple, trusted tools like archive files because they know users open them without hesitation. Once malware slips past detection, businesses face downtime, data loss, and costly recovery.
At CHIPS, we help organizations move beyond Detect and Respond and adopt an Isolation and Containment strategy with AppGuard.
Call to Action
Business leaders: do not wait for detection. Contact CHIPS to learn how AppGuard’s proven isolation-first protection can prevent incidents like the WinRAR zero-day before they begin.
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