FBI Warns of BlackByte Ransomware Attacks on Critical Infrastructure

The BlackByte ransomware has been used in attacks on at least three critical infrastructure sectors in the United States, the Federal Bureau of Investigation (FBI) and the U.S. Secret Service (USSS) warn in a joint advisory.

Available as a Ransomware-as-a-Service (RaaS), BlackByte has been used in attacks against US and foreign businesses, including in critical infrastructure sectors such as government, financial, and food and agriculture, the FBI and USSS warn.

BlackByte operators recently claimed to have obtained financial data from the San Francisco 49ers as a result of an attack that targeted the football team.

Some victims, the joint advisory says, discovered that the attackers exploited a known Microsoft Exchange Server vulnerability to gain initial access to their environments.

Next, the ransomware operators deployed tools that allowed them to move laterally on the network, and also attempted to elevate privileges before stealing and encrypting data.

Following a BlackByte attack, the victim typically finds a ransom note in all directories where files were encrypted. The note instructs the victim to access a website on the Tor network to pay a ransom in exchange for the decryption key.

[READ: SecurityWeek Cyber Insights 2022: Ransomware]

The FBI and the USSS also note that, in some incidents, files were only partially encrypted. “In cases where decryption is not possible, some data recovery can occur,” the advisory reads.

While previous versions of the ransomware downloaded a .png file before starting the encryption process, newer variants no longer communicate with external IP addresses.

The ransomware was observed spawning a process and injecting code into it, creating scheduled tasks and specific artifacts, dropping certain files, and executing specific commands.

The FBI-USSS joint advisory contains a long list of Indicators of Compromise (IoCs) associated with BlackByte, as well as recommendations on how organizations can mitigate the risk of ransomware.

Related: Ransomware Targeted 14 of 16 U.S. Critical Infrastructure Sectors in 2021

Related: 5 Ways to Reduce the Risk of Ransomware to Your OT Network

Related: CISA Warns of Threat Posed by Ransomware to Industrial Systems