BotnetPublished 6 Sep 2025

MeetC2 · A serverless C2 framework that leverages Google Calendar APIs as a communication channel

Source Reddit InfoSec News

Description

MeetC2 - A serverless C2 framework that leverages Google Calendar APIs as a communication channel Source: https://securityaffairs.com/181940/security/meetc2-a-serverless-c2-framework-that-leverages-google-calendar-apis-as-a-communication-channel.html

Impact

For European organizations, MeetC2 poses a significant threat due to its ability to evade traditional network defenses and blend malicious activity with legitimate cloud service usage. Organizations relying heavily on Google Workspace, including Google Calendar, are particularly vulnerable to this technique. The stealthy communication channel could facilitate persistent access by attackers, enabling prolonged espionage campaigns or ransomware deployments without easy detection. Confidentiality is at risk as attackers could use this channel to exfiltrate sensitive data or receive commands to manipulate or destroy data. Integrity and availability could also be compromised if attackers use the framework to deploy destructive payloads or disrupt services. Given the widespread adoption of Google services across European enterprises, especially in sectors such as finance, technology, and government, the potential impact is broad. Moreover, the difficulty in detecting such covert channels increases the risk of prolonged undetected intrusions, which can lead to significant financial losses, reputational damage, and regulatory penalties under frameworks like GDPR.

Defensive guidance

To mitigate the risks posed by MeetC2, European organizations should implement advanced monitoring of cloud API usage, specifically focusing on anomalous patterns in Google Calendar API calls. Behavioral analytics and anomaly detection tools can help identify unusual event creation or modification patterns that deviate from normal user behavior. Organizations should enforce strict access controls and least privilege principles for service accounts and API credentials associated with Google Workspace. Implementing endpoint detection and response (EDR) solutions capable of monitoring process behaviors and network connections can help detect suspicious activities related to MeetC2. Network segmentation and zero trust principles should be applied to limit lateral movement if an endpoint is compromised. Additionally, organizations should conduct regular threat hunting exercises focusing on cloud service abuse and educate security teams about emerging C2 techniques leveraging legitimate cloud platforms. Finally, maintaining up-to-date incident response plans that include scenarios involving cloud API abuse will improve readiness against such threats.

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Description

AI analysisMachine-generated, updated 6 Sep 2025, 11:50 UTC

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