cisa.gov Alert
Release DateNovember 24, 2025

CISA is aware of multiple cyber threat actors actively leveraging commercial spyware to target users of mobile messaging applications (apps).1 These cyber actors use sophisticated targeting and social engineering techniques to deliver spyware and gain unauthorized access to a victim’s messaging app, facilitating the deployment of additional malicious payloads that can further compromise the victim’s mobile device.

These cyber actors use tactics such as:

• Phishing and malicious device-linking QR codes to compromise victim accounts and link them to actor-controlled devices.
• Zero-click exploits,2 which require no direct action from the device user.
• Impersonation3 of messaging app platforms, such as Signal and WhatsApp.
  While current targeting remains opportunistic, evidence suggests these cyber actors focus on high-value individuals, such as current and former high-ranking government, military, and political officials,4 as well as civil society organizations (CSOs) and individuals across the United States,5 Middle East,6 and Europe.7

CISA strongly encourages messaging app users to review the updated Mobile Communications Best Practice Guidance and Mitigating Cyber Threats with Limited Resources: Guidance for Civil Society for steps to protect mobile communications and messaging apps, as well as mitigations against spyware.

• A fraudster develops or uses an automated bot or low-skilled workforce to trigger actions such as fake account creation, OTP requests, or password resets. These bots or human bots mimic real user activity, often bypassing security measures through direct API calls.
• These actions trigger SMS messages, which are sent to phone numbers controlled by the fraudster, creating inflated traffic.
• The fraudster collaborates with a “rogue party,” often a corrupt telecom provider or intermediary with access to SMS routing infrastructure.
• The rogue party intercepts the inflated SMS traffic, typically avoiding message delivery to reduce costs. Instead, they route the traffic to numbers they control.
• The rogue party earns revenue by collecting funds from the inflated SMS traffic, benefiting from volume-based pricing or other arrangements.

LY Corp., which operates popular messaging app Line and internet portal Yahoo! Japan, said Monday that an estimated 440,000 records of personal information may have been compromised by a third-party breach of its system.