The cybersecurity authorities of the Five Eyes intelligence alliance — the United States, Australia, Canada, New Zealand and the United Kingdom — released an alert Wednesday warning of potential malicious cyber activity resulting from Russia's invasion of Ukraine.

The alliance warned critical infrastructure network defenders to prepare for and mitigate potential cyber threats — including destructive malware, ransomware, DDoS attacks and cyber espionage — by hardening their cyber defenses, and offered defenders mitigation actions, as well as indicators of malicious activity.

The alert stated that the activity may occur as a response to the economic sanctions against Russia and material support the U.S. and allies have provided Ukraine since the invasion in February.

"Evolving intelligence indicates that the Russian government is exploring options for potential cyberattacks," the alert said.

The alert also noted that various cybercrime groups have pledged support of the Russian government, and have threatened to retaliate against perceived cyber offenses against Russia or its people.

An updated joint advisory by the five countries gives an overview of Russian state-sponsored cyber operations and commonly observed tactics, techniques and procedures (TTPs), as well as an overview of advanced persistent threat (APT) groups.