One runaway AI agent racked up a $50,000 cloud bill
Mandiant's AI Risk and Resilience report details prompt injection, AI supply chain compromises, agent abuse, and a runaway agent that accrued $50,000 in cloud charges.
Mandiant, drawing on Google Threat Intelligence Group (GTIG) observations, warns that poisoned data sources, model dependencies, and extension hooks can turn AI agents into channels for reconnaissance, lateral movement, and sandbox escape. Mandiant responded to incidents involving UNC6780 (TeamPCP), who stole AI service credentials and used prompt injection against AI coding assistants, while GTIG disclosed the first confirmed criminal use of an AI-developed zero-day exploit in a planned mass exploitation campaign. Red team tests showed an AI assistant manipulated into cloning internal repositories to an external GitHub account, and a runaway accounting agent made over 15,000 costly API calls in under an hour, generating roughly $50,000 in cloud charges.
Infostealer Logs Expose Replayable AI Tokens That Can Bypass MFA
Okta finds infostealer logs contain thousands of replayable AI session tokens and API keys, letting criminals bypass MFA and access services from Google, Anthropic and OpenAI.
Okta analyzed a 7 GB infostealer dump from August 2, 2026 covering 5,871 infected machines in 162 countries and found 555 of 44,791 JWTs related to AI services, plus 1,843 unexpired JWTs and JWEs (largely set by OpenAI via NextAuth.js) and 24 still-valid API keys for Google Gemini, OpenAI, Groq and OpenRouter. Valid session tokens and API keys can be replayed with anti-detect browsers like Camoufox to bypass credential and MFA checks, fueling an underground market for AI account access known as LLMjacking, where attackers rack up victims' AI compute bills. Some 17.7% of the JWTs contained plaintext PII usable for social engineering. Google's GTIG reported growing buyer demand for Claude, Gemini, Cursor and Devin credentials, and Mandiant handled an incident where an actor used an exposed GitHub PAT to deploy unauthorized AI infrastructure and scale high-performance compute.
Brand Impersonation Takedown: From Whack-a-Mole to Managed Response
Mandiant-tracked group UNC3753 impersonated US professional services firms' brands in 2026; Cyble urges managed takedowns over manual abuse reports.
Cyble describes how Google Mandiant-tracked group UNC3753 targeted US professional services firms between January and May 2026 using brand impersonation, spoofed domains, and fake executive profiles. Manual takedowns fail because phishing pages damage brands within hours while removal takes days. A managed takedown program with continuous monitoring and pre-authorized removal cuts the exposure window from days to hours.
Week in review: Records allegedly stolen from Azure tenants, Medusa ransomware hits 500+ orgs
Week in review: Medusa ransomware hit 500+ orgs per CISA, millions of Azure tenant records allegedly stolen, SafePal and French tax authority breaches disclosed.
Help Net Security's weekly roundup covers the FBI, CISA, and HHS joint advisory update reporting Medusa ransomware has breached more than 500 organizations since June 2021, and threat actor TheHatman's claim of millions of employee records stolen from Azure tenants of Fortune 500 firms including McDonald's, Vodafone, Kyndryl, and Tata Consultancy Services, per Hudson Rock. It also covers the SafePal breach affecting 39,798 customers, France's DGFiP breach exposing data on 678,000 individuals, and UT San delaying its fall semester after a cyberattack. Security items include critical unauthenticated GitLab flaw CVE-2026-19478, an actively exploited patched macOS Screen Sharing flaw deploying a cryptominer, US charges against 17 Mabna Institute Iranian hackers over 31TB of stolen academic data, and Google Mandiant's AI agents finding 100+ high-severity vulnerabilities.