Phobos Ransomware

Also Known As: Phobos virus
Distribution: Moderate
Damage level: Severe

Phobos ransomware removal instructions

What is Phobos?

Phobos is a ransomware-type malicious program that (like most programs of this type) encrypts data/locks files stored and keeps them in this state until a ransom is paid. Phobos renames all encrypted files by adding the ".phobos" extension plus the victim's unique ID and an email address. For example, "1.jpg" might be renamed to a filename such as "1.jpg.ID-63857777.[].phobos. Other variants of Phobos ransomware use the extension for encrypted files: ".[].Adair", ".[].deal", ".[].Caley", ".barak", ".zax", ".BANKS", ".banjo", ".[].acute", ".1500dollars", ".[].blend", ".[].adage", ".[].phobos", ".[].phobos", ".[].phoenix", ".[].phobos", ".[] .phobos", ". [] .phobos", ".[].phobos" or ".[].phobos". The email presented in the assigned extension varies. The virus encrypts data using AES cryptography and, after encryption, generates an HTML application ("Phobos.hta") and opens it. This app displays a pop-up window that contains a ransom-demand message.

In the ransom-demand message, cyber criminals state that all files are encrypted. To decrypt them, victims must contact them via the,, or other email addresses and provide the assigned ID ("Encryption ID"). Phobos developers offer free decryption of some files as 'proof' that they can be trusted and are capable of decryption (have the required decryption tool). They also urge victims to contact them immediately: supposedly, the sooner cyber criminals are contacted, the lower the cost of decryption. They also warn users of infected computers that only they can provide means to decrypt files. They state that any attempts to use other tools might result in permanent data damage (data loss). One victim contacted Phobos developers and received a response stating that cost of decryption (at that time) was $3000, however, they also stated that unless payment to a Bitcoin wallet (provided) was made within six hours, the cost would increase by $2000 (total cost of decryption tool would then be $5000). Typically, cyber criminals use cryptography algorithms that generate unique keys and are impossible to 'crack'. Furthermore, ransomware developers store these keys on remote servers controlled only by them. Decryption without involvement of cyber criminals is generally impossible, however, we recommended that you never trust these people or contact them - they ignore victims once ransom payments are made. If your computer is infected with Phobos, the best solution is to use an existing data backup and restore files from there. There is no tool currently capable of free file decryption.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

Phobos decrypt instructions

There are many ransomware-type programs, most of which are very similar. Examples include Seon, Nostro, and LyaS. The main purpose of these viruses is to encrypt data and to force victims to pay ransoms (typically in cryptocurrencies). The main differences are usually cost of decryption key/tool and cryptography algorithm used to encrypt the data. Only ransomware developers can provide victims with decryption keys/tools, and thus it is generally impossible to decrypt data without their involvement. This might only be possible if the virus is not fully developed or contains flaws/bugs. Therefore, create regular data backups and store them on remote servers or unplugged storage devices.

How did ransomware infect my computer?

There are several commonly used ways to infect computers with ransomware, however, it is not known exactly how cyber criminals proliferate Phobos. Typically, ransomware developers proliferate these infections through spam email campaigns, fake software updaters, dubious software download sources, and trojans. Spam campaigns infect computers through email attachments, which could be Microsoft Office documents, archive files, executables, PDF files, and so on. Cyber criminals send many emails containing malicious attachments hoping that some users will open them. Opening these attachments/installing malicious software usually results in computer infection with ransomware or other high-risk viruses. Fake software updaters often download and install malware rather than the promised updates, or exploit bugs/flaws of the outdated software. Cyber criminals use untrustworthy software download sources (such as freeware download websites, free file hosting websites, and peer-to-peer networks) to proliferate malicious files (executables) by presenting them as legitimate. By downloading and executing (running) them, malware (such as ransomware-type programs) is installed. Trojans are viruses (malicious programs) that, once installed, proliferate ransomware and other infections.

Threat Summary:
Name Phobos virus
Threat Type Ransomware, Crypto Virus, Files locker
Encrypted Files Extension .phobos (this ransomware also appends filenames with victim's unique ID and developers' email address)
Ransom Demanding Message Html application (Phobos.hta)
Cyber Criminal Contact,,,
Detection Names Avast (Win32:Trojan-gen), BitDefender (Gen:Variant.Ransom.Phobos.1), ESET-NOD32 (a variant of Win32/Filecoder.Phobos.A), Kaspersky (HEUR:Trojan.Win32.Generic), Full List Of Detections (VirusTotal)
Symptoms Can't open files stored on your computer, previously functional files now have a different extension, for example my.docx.locked. A ransom demanding message is displayed on your desktop. Cyber criminals are asking to pay a ransom (usually in bitcoins) to unlock your files.
Distribution methods Infected email attachments (macros), torrent websites, malicious ads.
Damage All files are encrypted and cannot be opened without paying a ransom. Additional password stealing trojans and malware infections can be installed together with a ransomware infection.
Malware Removal (Windows)

To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Malwarebytes.
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How to protect yourself from ransomware infections?

Take precautions when browsing the web, downloading, installing, and updating software. Avoid opening attachments presented in irrelevant emails. If you receive an email that contains an attachment (or web link) sent from an unknown/untrustworthy email address, do not open the attachment or click the presented link. Download software using official websites or other reliable sources. Do not use third party downloaders or other dubious tools. Do not use unofficial software updating tools - use tools or implemented functions that are provided by official software developers only. Have reputable anti-virus or anti-spyware software installed -  these tools can detect and eliminate various threats (computer infections) before they can do any damage. If your computer is already infected with Phobos, we recommend running a scan with Malwarebytes for Windows to automatically eliminate this ransomware.

Text presented in Phobos ransomware pop-up window:

All your files are encrypted
To decrypt your files, contact us using this e-mail: Please set topic 'Encryption ID: ********'.

We offer free decryption of your test files as a proof. You can attach them to your e-mail and we'll send you decrypted ones.
Decryption price increases over time, hurry up and get discount.
Decryption using third parties may lead to scam or increased price.

Screenshot of another variant of Phobos ransomware pop-up window:

another variant of Phobos ransomware pop-up window

Text presented in a second variant of Phobos ransomware pop-up window:

All your files are encrypted
Hello World
Data on this PC turned into a useless binary code
To return to normal, please contact us by this e-mail:,,
Set topic of your message to 'Encryption ID: ********'
Interesting Facts:
• 1. Over time, the cost increases, do not waste your time
• 2. Only we can help you, for sure, no one else.
• 3. BE CAREFUL !!! If you still try to find other solutions to the problem, make a backup copy of the files you want to experiment on, and play with them. Otherwise, they can be permanently damaged
• 4. Any services that offer you help or just take money from you and disappear, or they will be intermediaries between us, with inflated value. Since the antidote is only among the creators of the virus

Screenshot of files encrypted by Phobos (".phobos" extension that contains an ID and email address):

Files encrypted by Phobos

Phobos ransomware removal:

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Malwarebytes is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
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Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the Phobos virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the Phobos ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Phobos ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Phobos are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Phobos, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as Phobos ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the Documents, Pictures, Videos, Music, Favorites, as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove Phobos ransomware:

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

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Removal Instructions in other languages
Malware activity

Global malware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

QR Code
Phobos virus QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of Phobos virus on your mobile device.
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