# UAC-0099 used prompt text to disrupt AI malware analysis, researchers say

_Tuesday, September 1, 2026 at 4:26 AM EDT · Security, AI · Latest · Tier 2 — Notable_

![UAC-0099 used prompt text to disrupt AI malware analysis, researchers say — Primary](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiS-2JWiSkzpLkhR3nGp917yyeS4NATTlFhnDXcvmQdrc42BPgObEnlmwXMDP7fN8ruoEJ13Zru_lTVjPwTfU8aeSfK9uGt5H9dYK0s-STCiRMe4Wai1tgbeAU9CaaYZ9aIAZSDv3hVTD5UHKdCGNXGRkkrXDgsc0_3wHruuxZg4uRJDMhuSWSXKfgFanBb/s1700-nu-rw-lo-l85-e365/russian.jpg)

Cybersecurity researchers said Russia-aligned UAC-0099 inserted weapon-related text in a malicious VBS script to trigger safety mechanisms in AI-assisted analysis. ESET said the technique, dubbed GuardBreaker, was used against a target in Ukraine and was intended to stop an LLM from examining the rest of the script. The script downloads and installs the MATCHBOIL loader, which the source says is used exclusively by UAC-0099 to deliver further payloads.

## Sources

- [The Hacker News](https://thehackernews.com/2026/09/russia-aligned-uac-0099-plants-nuclear.html)

---
Canonical: https://techandbusiness.org/newswire/6hLfW0jAG6Cw_Li2MNbvP6
Retrieved: 2026-09-01T11:16:09.156Z
Publisher: Tech & Business (techandbusiness.org)