Google Calendar is a popular tool for managing appointments and events, but it is also a potential target for hackers. In June 2023, a researcher named Valerio Alessandroni published a proof-of-concept (PoC) exploit called “Google Calendar RAT” that allows hackers to use Google Calendar events as a covert command-and-control (C2) channel.
The Google Calendar RAT creates a new calendar event with a malicious description. The target machine is then programmed to check the event description for new commands periodically. When the target machine finds a command, it executes it and then updates the event description with the output.
This process is repeated, allowing the hacker to control the target machine without detection. The fact that the Google Calendar RAT operates exclusively on legitimate infrastructure makes it even more challenging to detect.
In November 2023, Google warned that threat actors were sharing the Google Calendar RAT PoC online and using it to attack real-world targets. Google has since released a patch for the vulnerability, but users are still advised to be vigilant.
How to protect yourself from the Google Calendar RAT
There are a few things you can do to protect yourself from the Google Calendar RAT:
- Make sure your Google Calendar is up to date. Google has released a patch for the vulnerability, so it is crucial to install it as soon as possible.
- Be careful about clicking on links in calendar events. If you receive an event from an unknown sender or if the event description looks suspicious, do not click on any links.
- Use a strong password for your Google account and enable two-factor authentication. This will help to protect your account from being compromised.
- Keep your operating system and security software up to date. This will help to protect you from other known vulnerabilities.
The Google Calendar RAT is a new and innovative way for hackers to attack. It is essential to be aware of this vulnerability and to take steps to protect yourself. By keeping your software up to date and being careful about what links you click on, you can help to keep your devices safe.
Additional preventative tips for businesses
In addition to the tips above, businesses should also consider the following to protect themselves from the Google Calendar RAT:
- Brief employees about the Google Calendar RAT and how to avoid it.
- Implement security policies that restrict access to Google Calendar and other cloud services.
- Use a security information and event management (SIEM) solution to monitor Google Calendar activity for suspicious activity.