Microsoft Threat Intelligence reported that threat actors are exploiting the popularity of AI platforms including ChatGPT, Claude, DeepSeek, and Flux Pro AI to drive phishing, malvertising, and malware delivery rather than compromising the vendors themselves. One ChatGPT-themed campaign, aimed largely at South African users, used payment-update emails and redirect chains through legitimate services to a compromised site that harvested personal and credit card data. A separate Claude-themed operation targeted more than 2,000 organizations and likely used adversary-in-the-middle techniques to steal Microsoft sign-in credentials and authentication tokens.
Microsoft also linked large-scale AI-themed malvertising to Storm-3075, which pushed fake AI plugin downloads and delivered malware including Vidar Stealer, Lumma Stealer, Hijack Loader, and Oyster, with parts of the chain tied to Fox Tempest malware-signing services. In another case, attackers created a fake DeepSeek V4 GitHub repository within hours of the model’s launch, using copied benchmark data, official-looking branding, SEO tactics, and rotating payloads to distribute Vidar and GhostSocks malware before GitHub removed the infrastructure. Microsoft said it revoked certificates, disrupted Fox Tempest infrastructure with partners, and coordinated takedowns, while urging defenders to strengthen MFA, conditional access, browser protections, and endpoint and email defenses.

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11 events from the most recent confirmed update back to the earliest known activity.
Researchers reported a high-severity campaign using lookalike .ru domains impersonating DeepSeek, MiniMax, and ChatGPT to target Russian-speaking users. The fake sites used cloned AI branding and chat-style interfaces, then monetized victims through fraudulent premium AI subscription offers processed via legitimate Stripe infrastructure.
Straiker reported a campaign using fake Claude Code and other developer-platform documentation sites, boosted by SEO poisoning, redirect chains, and paid Google ads, to trick users into running malicious installation commands. The operation involved more than 88 fake domains and delivered ACRStealer and a cryptocurrency clipboard hijacker while targeting AI-related credentials such as API keys, auth tokens, and cloud development secrets.
Microsoft described a ChatGPT-branded phishing campaign that sent 4,500 emails to targets in South Africa. The activity was linked to broader infrastructure capable of sending up to 100,000 emails in a single day to targets in Switzerland, Austria, and South Africa.
FortiGuard Labs disclosed a high-severity Windows malware campaign using AI-themed lures in compressed archives and malicious LNK files to deploy a staged infection chain ending in a modular .NET RAT and AsyncRAT. Fortinet said the malware used persistence, defense evasion, and command-and-control infrastructure including 107[.]172[.]10[.]190 and several lookalike domains, and that its security products detect or block the activity.
Microsoft Threat Intelligence documented an early-2026 phishing campaign abusing Claude branding to conduct adversary-in-the-middle token theft. The operation targeted more than 2,000 organizations in the United States, United Kingdom, and India.
Microsoft said it and partners disrupted infrastructure associated with Fox Tempest, a malware-signing-as-a-service operation tied to signed malware used in AI-themed malvertising chains. The disruption was noted as having occurred in May 2026.
On June 8, 2026, Microsoft published a report describing multiple 2026 campaigns abusing AI brands such as ChatGPT, Claude, DeepSeek, and Flux Pro AI for phishing, malvertising, and malware delivery. The company said the activity reflected abuse of brand names rather than compromise of the legitimate AI vendors.
TrendAI Research reported that in May 2026 attackers pivoted from GitLab Pages to Claude.ai shared chat URLs to host ClickFix social-engineering instructions impersonating Apple Support and development teams. The campaign used Google Ads and AI-themed lures to trick victims into running commands that fetched the MacSync infostealer, with activity concentrated in Asia-Pacific before expanding to India, France, and Italy.
After the fake DeepSeek V4 campaign was identified, GitHub removed the malicious repository, organization, and user account used in the operation. Microsoft assessed the activity as part of a broader ecosystem that rebrands malware around trending AI products rather than a compromise of DeepSeek itself.
On April 24, 2026, attackers created a fake GitHub repository impersonating DeepSeek V4 within hours of the model's launch and used it to distribute malware. Microsoft said victims began downloading the malware within four hours, and the payloads were linked to Vidar infostealer and GhostSocks proxy malware.
Trend Micro said a multi-wave malicious advertising and impersonation campaign began on April 8, 2026 using GitLab Pages-hosted lure pages impersonating Claude, ChatGPT, Codex, Perplexity, Mac utilities, and JetBrains themes. The operation used Google Ads to drive traffic and later evolved into the Claude.ai shared-chat abuse already documented elsewhere.
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