AttriGuard: Defeating Indirect Prompt Injection in LLM Agents Via Causal Attribution of Tool Invocations

LLM agents are highly vulnerable to Indirect Prompt Injection IPI, where adversaries embed malicious directives in untrusted tool outputs to hijack execution. Most existing defenses treat IPI as an input-level semantic discrimination problem, which often fails to generalize to unseen payloads. We...

When Bots Take the Bait: Exposing and Mitigating the Emerging Social Engineering Attack in Web Automation Agent

Web agents, powered by large language models LLMs, are increasingly deployed to automate complex web interactions. The rise of open-source frameworks e.g., Browser Use, Skyvern-AI has accelerated adoption, but also broadened the attack surface. While prior research has focused on model threats su...

XLM + AMSI: New runtime defense against Excel 4.0 macro malware

We have recently expanded the integration of Antimalware Scan Interface AMSI with Office 365 to include the runtime scanning of Excel 4.0 XLM macros, to help antivirus solutions tackle the increase in attacks that use malicious XLM macros. This integration, an example of the many security feature...