What happened
Germany’s Federal Office for the Protection of the Constitution (BfV) and the Federal Office for Information Security (BSI) issued a joint cybersecurity advisory detailing a sophisticated phishing campaign that uses social engineering to compromise accounts on the encrypted messaging app Signal without deploying malware.
Who is affected
The campaign focuses on high-value individuals, including politicians, military officials, diplomats, and investigative journalists, across Germany and Europe, though similar tactics could extend to other secure messaging platforms with device-linking features.
Why CISOs should care
Threat actors are exploiting user trust and native app features to bypass encryption protections and gain unauthorized account access, enabling account takeovers, real-time message interception, contact list exposure, and potential impersonation. This risk underscores the limitations of technical controls when human behavior is manipulated and highlights how secure communications tools can become vectors for broader network compromises if not properly safeguarded.
3 practical actions
- Strengthen account-level defenses: Enforce enabling Registration Lock and similar platform-provided protections to prevent unauthorized re-registrations.
- Educate high-risk users: Train executives, key personnel, and journalists on identifying and avoiding social-engineering phishing lures, including unsolicited support messages and QR code prompts.
- Monitor linked devices and security settings: Regularly audit linked devices on messaging apps and remove unknown entries; implement out-of-band verification for any requested authentication changes.