A new ransomware threat – Ako ransomware – has emerged which is targeting business networks and is being distributed via spam email. The ransomware is being offered to affiliates under the ransomware-as-a-service model and the aim of the attackers is clear. To maximize the probability of payment of the ransom by making recovery harder, and to steal data prior to encryption to ensure the attack is still profitable if the ransom is not paid. Having the data could also help convince the victims to pay up, as we have seen in recent attacks involving Maze and Sodinokibi ransomware, where threats are issued to publish stolen data if the ransom is not paid.
The developers of Ako ransomware appear to be going for large ransom payments, as they are not targeting individual workstations, rather the entire network. The ransomware scans local networks for other devices and will encrypt network shares. The ransomware deletes shadow copies and recent backups and disables Windows recovery to make recovery more difficult without paying the ransom.
Encrypted files are given a randomly generated file extension and retain the original file name. No ransom amount is stated in the ransom note. Victims are required to contact the attackers to find out how much they will need to pay for the keys to decrypt their files.
One of the intercepted emails being used to distribute the ransomware uses a password-protected zip file as an attachment. The email appears to be a business agreement which the recipient is asked to check. The password to open and extract the file is included in the message body. The zip file attachment – named agreement.zip – contains an executable file which will install Ako ransomware if it is run. The malicious file is called agreement.scr.
There is no free decryptor for Ako ransomware. Recovery without paying the ransom will depend on whether viable backups exist that have not also been encrypted. It is therefore important to make sure backups are regularly performed and at least one copy of the backup is stored on a non-networked device to prevent it also being encrypted by the ransomware. Backups should also be tested to make sure file recovery is possible.
Since Ako ransomware is being distributed via spam email, this gives businesses an opportunity to block an attack. An advanced spam filtering solution should be implemented that scans all inbound messages using a variety of detection mechanisms to identify malware and ransomware threats. A sandbox is an important feature as this will allow email attachments to be analyzed for malicious activity. This feature will improve detection rates of zero-day threats.
nd user training is important to ensure that employees do not open potentially malicious files. Training should condition employees never to open email attachments in unsolicited emails from unknown senders. As this campaign shows, any password protected file sent in an unsolicited email is a big red flag. This is a common way that ransomware and malware is delivered to avoid detection by antivirus solutions and spam filters.
Anti-spam solutions and antivirus software will not be able to detect the threat directly if malicious files are sent in password-protected archives, which can only be opened if the password is entered. Rules should therefore be set to quarantine password-protected files, which should only be released after they have been manually checked by an administrator. With SpamTitan, these rules are easy to set.
Ako ransomware is one of many new ransomware threats that have been released in recent months. High profile attacks on companies such as Travelex that see massive ransom demands issued, which in many cases are paid, show a huge payday is possible.
Ransomware developers will keep developing new threats for as long as attacks remain profitable, and there is not likely to be a shortage of affiliates willing to run spamming campaigns to get their slice of the ransom payments.
With the attacks increasing, it is essential for you to have strong defenses that can detect and block malware, ransomware, and phishing threats, and that is an area where TitanHQ can help.
To find out more about how you can improve your defenses against email and web-based threats, give the TitanHQ team a call today.