Suspicious Error 524 Decoy Smishing Phishing Endpoint Access (via proxy)

ATT&CK techniques

Initial Access → Exfiltration

Recon
Resource Dev
Initial Access
- T1566.002Spearphishing Link
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1071.001Web Protocols
Exfiltration
- T1041Exfiltration Over C2 Channel
Impact

What it detects

This rule detects access to the single-page phishing endpoints used by the Error 524 decoy smishing campaign, including getApp application-id lookups and WebSocket uuid exfiltration paths. The campaign hides credential and card data theft behind fake Cloudflare Error 524 pages. Detecting these URIs reveals victims interacting with the phishing infrastructure.

Reporting behind it

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Suspicious Error 524 Decoy Smishing Phishing Endpoint Access (via proxy)

Pivot detection · T1041 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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