ESET Advises Nigerian Companies on ‘Jaff / WannaCryptor’ Ransomware

ESET is aware of several ransomware outbreaks that stem from malicious emails that can be used to introduce threats to your system.

ESET identifies these threats as Filecoder.WannaCryptor and Filecoder.NLI (Jaff), and ESET detects and blocks these threats and their variants. Click here for a list of best practices to stop these threats.

There were reports from our offices across Europe on how fast the spread is and major hospitals, ISPs and Telecommunication companies have already fell victim of the attack. The malicious email campaign stems from the Necurs botnet and spreads the new ransomware at the rate of more than 5 million emails per hour and hitting computers across the globe.

Typically, once the victim is infected, their files are encrypted. Unlike the traditional ransomware which leaves a note of the amount required for payment, Jaff Filecoder would advise the victim to visit a payment portal via a Tor site to decrypt their valuable files, says Olufemi Ake.

ESET products can detect and block this malware. As an existing ESET client, we strongly recommend that you follow the suggestions below to ensure the highest level of security on your computer:

• Make sure that ESET Live Grid is enabled in your ESET product.

• Make sure that your ESET software is upgraded to the latest version and has the latest Virus Signature Database updates.

• Do not open attachments sent to you in emails from unknown senders. We also recommend that you avoid opening unsolicited email attachments from someone you know and trust.

• Warn colleagues who frequently receive emails from external sources – for instance financial departments or Human Resources.

• Regularly back up your data. In the event of infection, this will help you recover all data. Do not leave external storage used for backups connected to your computer to eliminate the risk of infecting your backups. If your system requires Windows Updates to receive the patch for this exploit, create new backups after applying the patch.

• Disable or restrict Remote Desktop Protocol (RDP) access (see Remote Desktop Protocol best practices against attacks).

• Disable macros in Microsoft Office.

• If you are using Windows XP, disable SMBv1.

For more detailed information about how you can use ESET to protect your systems from ransomware infections, see the following Knowledgebase article:

‘Best practices to protect against Filecoder (ransomware) malware’