A large-scale brute force password attack using almost 2.8 million IP addresses is underway, attempting to guess the credentials for a wide range of networking devices, including those from Palo Alto Networks, Ivanti, and SonicWall.

A brute force attack is when threat actors attempt to repeatedly log into an account or device using many usernames and passwords until the correct combination is found. Once they have access to the correct credentials, the threat actors can then use them to hijack a device or gain access to a network.

According to the threat monitoring platform The Shadowserver Foundation, a brute force attack has been ongoing since last month, employing almost 2.8 million source IP addresses daily to perform these attacks.