Ransomware gangs may take advantage of upcoming holidays and weekends to hit US organizations, the FBI and the CISA have warned.

Using the recent Colonial Pipeline, JBS, and Kaseya ransomware attacks as examples – since they happened in the lead-up to or during Mother’s Day weekend, Memorial Day weekend and the Fourth of July holiday weekend, respectively – the agencies note that organizations should be aware of these new tactics and prepare to counter them.

“This additional time gives attackers the ability to exfiltrate more sensitive data or lock up more computers with ransomware than they otherwise might have been able to. In addition, timing attacks for long holiday weekends to maximize harm can also be attractive to adversarial nation states looking to deal the most damage to the United State’s economy and infrastructure. Organization’s must adopt a true culture of security that includes attack timing into their threat model to ensure that they are not caught flat footed by staffing shortages during holiday breaks.”

As the agencies pointed out, ransomware attackers are increasingly doing more than just encrypting organizations’ IT assets: they are also encrypting or deleting system backups, and threatening to publicly name affected victims and release sensitive or proprietary data they exfiltrated before encryption.

Ransomware gangs don’t discriminate: they will targeted large, lucrative organizations, but also SMBs. The FBI and CISA encourage organizations “To examine their current cybersecurity posture and implement the recommended best practices and mitigations to manage the risk posed by all cyber threats, including ransomware.”

Finally, CISA offers free cybersecurity assessment services for various levels of governments, as well as public and private sector critical infrastructure organizations.