Pierluigi Paganini January 29, 2022

QNAP forces its customers to update the firmware of their Network Attached Storage (NAS) devices to protect against the DeadBolt ransomware.

QNAP forced the firmware update for its Network Attached Storage (NAS) devices to protect its customers against the DeadBolt ransomware.

DeadBolt ransomware is targeting QNAP NAS devices worldwide, its operators claim the availability of a zero-day exploit that allows them to encrypt the content of the infected systems.

Once encrypted the content of the device, the ransomware appends .deadboltextension to the name of the excerpted files and deface the login page of the QNAP NAS to display the following message:

“WARNING: Your files have been locked by DeadBolt”

The hijacked QNAP login screen displays a ransom note demanding the payment of 0.03 BTC ransom (roughly $1017) to receive a decryption key to recover the files.

Operators claim a transparent process for the delivery of the decryption key directly to the Bitcoin blockchain. The decryption key is stored directly in the OP_RETURN field of a transaction made by the operators in response to the payment. Victims can retrieve the key by monitoring the address they have they made the ransom payment.

After payment is made, the threat actors claim they will make a follow-up transaction to the same address that includes the decryption key (composed of 32 characters), which can be retrieved using the following instructions.

The ransom note also includes a link titled “important message for QNAP,” which points to a page that offers technical details of the alleged zero-day vulnerability in QNAP NAS devices for 5 BTC (approximately $184,000).

Bleeping Computer reported that the ransomware has already encrypted over 3,600 devices and many users of its DeadBolt support forum topic reported that they were able to recover their files by paying the ransom.

Searching for encrypted NAS exposed online with Shodan search engine we can find that more than 1200 devices exposed online have been encrypted. Making similar research with the Censys search engine, the number of compromised NAS devices is treated than 4,000.

In response to the numerous infections, the Taiwanese vendor initially warned customers to install the latest QTS software version, and disable UPnP and port forwarding. Then QNAP opted to force-updated the firmware for all customers’ NAS devices to version 5.0.0.1891, which is the latest firmware version released on December 23, 2021.

“We are trying to increase protection against deadbolt. If recommended update is enabled under auto-update, then as soon as we have a security patch, it can be applied right away.” states the vendor.

“Back in the time of Qlocker, many people got infected after we had patched the vulnerability. In fact, that whole outbreak was after the patch was released. But many people don’t apply a security patch on the same day or even the same week it is released. And that makes it much harder to stop a ransomware campaign. We will work on patches/security enhancements against deadbolt and we hope they get applied right away. I know there are arguments both ways as to whether or not we should do this. It is a hard decision to make. But it is because of deadbolt and our desire to stop this attack as soon as possible that we did this.”

This update also included numerous security fixes, but almost all of them are related to Samba, which is unlikely associated with this attack.

QNAP owners and IT admins told BleepingComputer that QNAP forced this firmware update on devices even if automatic updates were disabled.

Bleeping Computer reported that some users faced problems due to the update, their iSCSI connections to the devices were no longer working after the update. 

Below is the fix proposed by a QNAP owner on Reddit:

“Just thought I would give everyone a heads-up. A couple of our QNAPS lost ISCSI connection last night. After a day of tinkering and pulling our hair out we finally found it was because of the update.
It has not done it for all of the QNAPs we manage but we finally found the resolution. In “Storage & Snapshots > ISCSI & Fiber Channel” right-click on your Alias (IQN) select “Modify > Network Portal” and select the adapter you utilize for ISCSI.”

Some users claim that the firmware update removes the ransomware files and ransom note used to allow victims of the attack to decrypt their files making it impossible to pay the ransom.

QNAP continues to be a privileged target for cybercriminals, recently a new wave of Qlocker ransomware was observed targeting QNAP NAS devices worldwide. In December 2021, another wave of ech0raix ransomware attacks started targeting QNAP network-attached storage (NAS) devices.

Follow me on Twitter: @securityaffairs and Facebook

Pierluigi Paganini

(SecurityAffairs – hacking, QNAP)

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