Ransomware actors are again using TeamViewer to gain initial access to organization endpoints and attempt to deploy encryptors based on the leaked LockBit ransomware builder.
A similar case was first reported in March 2016, when numerous victims confirmed in the BleepingComputer forums that their devices were breached using TeamViewer to encrypt files with the Surprise ransomware.
“As TeamViewer is a widely spread software, many online criminals attempt to log on with the data of compromised accounts, in order to find out whether there is a corresponding TeamViewer account with the same credentials,” explained the software vendor at the time.
A new report from Huntress shows that cybercriminals haven’t abandoned these old techniques, still taking over devices via TeamViewer to try and deploy ransomware.
While Huntress hasn’t been able to attribute the attacks with certainty to any known ransomware gangs, they note that it is similar to LockBit encryptors created using a leaked LockBit Black builder.
This sample is detected as LockBit Black but does not use the standard LockBit 3.0 ransomware note, indicating it was created by another ransomware gang using the leaked builder.