Mailto (NetWalker) Ransomware Targets Enterprise Networks


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Mailto (NetWalker) Ransomware Targets Enterprise Networks (Feb 5, 2020)

A new ransomware identified in 2019 called “Mailto”, also known as NetWalker has recently targeted an Australian transportation and logistics company called, Toll Group. The ransomware was seen spoofing “sticky password” software. When the file is executed it uses an embedded config file containing the ransom note and filename extensions. The ransomware will append an extension using the format .mailto[{mail1}].{id}. Coveware, an incident response company specialising in ransomware, discovered a decrypter indicating the ransomware is called NetWalker.

Recommendation: Always run antivirus and endpoint protection software to assist in preventing ransomware infection. Maintain secure backups of all your important files to avoid the need to consider payment for the decryption key, and implement a business continuity plan in the unfortunate case of ransomware infection. Emails received from unknown sources should be carefully avoided, and attachments and links should not be followed or opened. Your company should sustain policies to consistently check for new system security patches. In the case of ransomware infection, the affected systems should be wiped and reformatted, even if the ransom is paid. Other machines on the same network should be scanned for other potential infections.

Indicators of Compromise (IOCs) associated with this story can be viewed by ThreatStream users here to identify potential malicious activity.