Octopus ransomware – a dangerous cyber infection that asks for 0.31 BTC for the encrypted file recovery
Octopus ransomware is a Phobos virus variant that was first spotted in the wild in early November 2019 and is known to be spread via poorly protected RDP connections.[1] Just as its predecessors, malware aims to encrypt all personal data on the machine and the connected networks/drives and then blackmail victims into paying a ransom in Bitcoin for the decryption software that only developers of Octopus virus have access to. In the case of this version, all personal pictures, videos, images, documents, databases, MS Office, and other files get marked with .octopus file extension and are no longer available to be used.
After file encryption, Octopus ransomware delivers two ransom notes: info.txt, which is a standard message from the perpetrators and info.hta – a pop-up window that shows more detailed instructions. The attackers ask victims to contact them via octopusdoc@mail.ee or octopusdoc@mail.cc emails, and then demand the ransom to be paid for the decryption tool. While the price might vary (criminals do not specify the ransom amount in the message), in the known instances, they demanded 0.31 BTC for file release.
| Threat name | Octopus ransomware |
| Type | Cryptovirus |
| Malware family | Phobos ransomware |
| Infection means | Octopus virus is known to be spread via Remote Desktop connections, although malware might be distributed via other methods, such as spam emails, fake updates, software cracks, exploits, etc. |
| Encryption method | Ransomware uses the AES encryption algorithm to lock all personal data on the infected device |
| File extension | All personal pictures, videos, documents, etc., are appended with .octopus marker, although full file modification looks as follows: [name].[original extension].id[XXXXXXXX-XXXX].[octopusdoc@mail.ee].octopus. Example of an encrypted file: instructions.pdf.id[8E95D737-2497].[octopusdoc@mail.ee].octopus |
| Ransom note | Two ransom notes are placed on the infected machine: info.txt (brief), info.hta (an extensive note that is shown in a pop-up window) |
| Contact | Victims are asked to contact cybercriminals to begin ransom payment negotiations via octopusdoc@mail.ee or octopusdoc@mail.cc |
| Ransom size | 0.31 Bitcoin (may vary) |
| Termination | Use reputable anti-malware software to locate and eliminate the malicious components from your system |
| File decryption | The only safe way to decrypt .octopus files is by restoring them from backups that were set up prior to the infection. In case no backups are available, the only option is to try data recovery software – check out the guide below |
| Recovery | Ransomware might render the system partially broken, as anti-malware software cannot repair some ransomware-affected system files. Due to this, OS reinstallation might be sometimes necessary. To avoid that, we recommend using a repair tool FortectIntego |
Phobos is one of the most well-established ransomware families in the wild – it accounts for around 9% of worldwide infections of cryptolockers.[2] While it mostly targets corporations and public entities, Octopus ransomware might infect regular PC users as well. The main propagation method of this malware strain is via the RDP connections, credentials of which were stolen by other cybercriminal groups and sold on the black market. Since late December 2018, the malware is establishing a name for itself, as it released dozens of versions throughout its short time of the operation (in comparison to other ransomware families like Djvu).
Once installed, Octopus ransomware starts preparing a Windows system for the file encryption process:
- Deletes Shadow Volume Copies
- Establishes a network connection with C&C server
- Deletes, installs and opens various registry entries
- Executes Shell Commands, etc.
System modifications might also prevent easy Octopus ransomware removal by hindering System Restore function or disabling anti-malware software. To avoid that, victims should access Safe Mode with Networking to temporarily pause these effects.
After that, Octopus ransomware initiates the file encryption process with AES cipher, and each of the files located on the host computer receives .octopus extension, although the complete extension looks as follows: instructions.pdf.id[8E95D737-2497].[octopusdoc@mail.ee].octopus – the ID varies based on the victim.
The Octopus virus ransom note info.txt states the following:
!!!All of your files are encrypted!!!
To decrypt them send e-mail to this address: octopusdoc@mail.ee.
If we don't answer in 24h., send e-mail to this address: octopusdoc@airmail.cc
Another note, which comes as a pop-up window, explains everything in more detail – users are informed that they can get a test decryption service. Crooks offer to decrypt up to five files for free, as long as they do not include valuable information. However, this is one of the tricks that many ransomware authors use, and Octopus ransomware developers are no exception – they are trying to gain victims' trust and prove the decryption is possible.
Nevertheless, there were several instances where users did not receive the decryption tool, even after paying the ransom. Therefore, paying crooks is always a risk, as loss of money along with loss of files might be devastating to many. Instead, users should remove Octopus ransomware by scanning the computer with anti-malware. To repair the system after the infection, we recommend using FortectIntego. One of the alternatives to paying criminals is trying data recovery software – check out the recovery section below for more details.
Secure your Remote Desktop connection to prevent ransomware attacks
Phobos is a large malware family, and most of the attacks are performed with brute-force attacks – cybercriminals scan the internet for insecure Remote Desktop (RDP) connections and then use a predetermined list of credentials to gain remote access to the host machine. In some cases, the credentials might be acquired from the underground forums due to data leaks in various security breaches.
Once the access is granted, malicious actors can control the computer remotely and, while the brute-forcing process is usually automated, they download and install the malicious payload manually. This allows hackers to act “on the spot,” and this method has been extremely prevalent when corporate entities and high-profile victims are targeted.[3]
To avoid ransomware attacks via RDP, adequate protection measures should be employed. Security experts[4] advise the following:
- Disconnect from the Remote Desktop as soon as the feature is not needed anymore;
- Use strong passwords and change them frequently – do not reuse them;
- Never use default TCP port for your connection – 3389, as attackers can easily identify;
- Keep all your software updated so that hackers could not abuse software vulnerabilities to get into your machine.
Because bad actors can use several other methods for malware distribution (spam email, software cracks, fake updates, etc.), it is vital to protect your machine with reputable anti-malware solutions.
Attempt to restore your files only after you remove Octopus ransomware from your machine
While it is possible to remove Octopus ransomware manually, it is a huge task even for IT professionals. Malware makes thousands of changes to the infected systems, and reverting them might be extremely difficult and would take an enormous amount of time. Thus, this operation should be conducted with powerful anti-malware software – it would detect all the malicious components on the infected Windows machine and eliminate them at once. However, the Octopus virus might prevent security software from operating normally. In such a case, you should access Safe Mode and perform a full scan from there – we explain how to do that below.
Only after you complete Octopus ransomware removal, you can proceed with the data recovery process. If the opposite is performed, all the recovered files will be encrypted by the virus repeatedly, making the whole restoration process useless. Before you do that, however, you should backup all the encrypted files, as the data might get corrupted in the process.
While there is no Octopus ransomware decryptor available from security researchers, you might be able to get at least some of your data back by using data recovery software – find the download links and usage instructions below.
Was this guide helpful?
Be the first to comment