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Attackers exploited critical Atlassian flaw CVE-2026-21589 within hours, alongside arrests, malware updates, and certificate hijacks.
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Attackers exploited critical Atlassian flaw CVE-2026-21589 within hours, alongside arrests, malware updates, and certificate hijacks.

CISA added an exploited NetScaler flaw to KEV as Atlassian, Exchange, and SonicWall patches landed amid active attacks.

UAC-0099's MATCHBOIL downloader hides C2 behind Cloudflare and delivers MATCHWOK to Ukrainian firms.

UAC-0099's MATCHBOIL downloader evolved with sandbox checks, .NET Reactor obfuscation, scheduled-task persistence, and recurring C2, hitting Ukrainian transport and energy firms.

Cyber-espionage actor UAC-0099 has upgraded its MatchBoil dropper with stealthier capabilities for ongoing campaigns against Ukrainian organizations.

Russia-aligned UAC-0099 deployed the ASHVEIN RAT against Ukrainian government staff, hiding tasking in HTML.

ESET documents two years of UAC-0099 upgrades to its MATCHBOIL downloader used in espionage against Ukrainian government, energy and transport sectors.
UAC-0099 upgraded MatchBoil malware in espionage attacks on Ukrainian transport and energy firms.

Russia-aligned UAC-0099 uses MATCHBOIL to install the MATCHWOK spy backdoor on Ukrainian transport, manufacturing, and energy firms.

Russia-aligned group UAC-0099 embeds GuardBreaker prompt injection in a VBScript comment to make AI malware scanners refuse analysis of a MATCHBOIL loader.

ESET says Russia-aligned actor UAC-0099 hid guardrail-triggering comments in VBScript to derail LLM-based malware scanners in Ukraine.

ESET names 'GuardBreaker': UAC-0099 embeds a nuclear-weapon question in VBScript comments to trip LLM scanner guardrails during analysis of its MATCHBOIL loader.

Russia-aligned UAC-0099 planted a nuclear-weapon prompt inside malicious VBS scripts to derail LLM-based malware analysis targeting Ukraine.

ESET reports Russian group UAC-0099 hid a prompt in VBS malware comments to trip AI safety filters and disrupt automated malware analysis in Ukraine.
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