Opening SecureFlowSpyder: Sider Cross-Origin Synthetic-Gesture Attack
Case summary & sources

AIDEFEND SecureFlow / SecureFlow Case Index

Rebora Security Research aidefend-sf0041

Spyder: Sider Cross-Origin Synthetic-Gesture Attack

  • Edge & Client AI
  • Copilot & SaaS
  • Data Exfiltration
  • Credential & Identity Theft

Rebora's Spyder research used a synthetic dragstart event to trigger Sider's link-preview path and remove iframe restrictions. The attacker page then reached the embedded authenticated Gemini session through an open Shadow DOM and iframe WindowProxy, issued hidden click and type commands, requested recent information, created a share link, and leaked that URL. An August 25 static check of Sider 5.32.2 found isTrusted on the disclosed drag entry and no disclosed clickAt handler; this is not a full exploit retest or vendor confirmation.

Mapped threat techniques

  • AML.T0011.003 User Execution: Malicious Link
  • AML.T0107 Exploitation for Defense Evasion
  • AML.T0053 AI Agent Tool Invocation
  • AML.T0025 Exfiltration via Cyber Means

Source

Updated