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Calisto macOS Backdoor

Calisto is a backdoor trojan targeting macOS. First observed in 2016, it has only recently begun to be detected by major anti-virus vendors.
Threat ID:
CC-2547
Category:
Trojan
Threat Severity:
Low
Threat Vector:
Download
Published:
25 July 2018 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

This content has been archived

This article no longer conforms to NHS Digital's standards for cyber alerts, and may contain outdated or inaccurate information. Use of this information contained in this page is at your own risk

Summary

Calisto is a backdoor trojan targeting macOS. First observed in 2016, it has only recently begun to be detected by major anti-virus vendors.

Affected platforms

The following platforms are known to be affected:

macOS

  • Apple macOS - All versions

Threat details

At the time of publication it is unclear how Calisto is distributed although there are unconfirmed reports it is delivered via spam or phishing campaigns as a unsigned copy of Intego's 'Mac Internet Security X9' anti-virus software.

Once installed, Calisto will collect several types of information including:

  • Keychain encryption keys
  • User and system information
  • Google Chrome browsing history, bookmarks and cookies

It will also set itself to run automatically on startup before initiating a connection to a command and control server, at which point it will transfer all collected data and await further commands.

Remediation steps

Type Step

Calisto's functionality can be severely limited by enabling System Integrity Protection (SIP). SIP limits what actions can be performed on protected macOS software section by restricting the permissions of root users. By default SIP is enabled on OS X El Capitan and later devices but can often be disabled by users.

To prevent and detect a trojan infection, ensure that:

  • A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails.
  • All operating systems, anti-virus and other security products are kept up-to-date.
  • All day-to-day computer activities such as email and internet are performed using non-administrative accounts.
  • Strong password policies are in place.
  • Network, proxy and firewall logs should be monitored for suspicious activity.
  • User accounts accessed from affected devices should be reset on a clean computer.
  • Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

 

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Last edited: 17 February 2020 12:39 pm