ASN1 Ransomware

Also Known As: asn1 virus
Distribution: Low
Damage level: Severe

ASN1 ransomware removal instructions

What is ASN1?

First discovered by MalwareHunterTeam, ASN1 is a ransomware-type virus that stealthily infiltrates the system and encrypts stored files. Cyber criminals spread ASN1 via spam emails (malicious attachments). Following infiltration, ASN1 encrypts files using asymmetric cryptography, unlike other ransomware-type viruses, it does not rename encrypted files or append extensions. Following successful encryption, ASN1 opens a pop-up window and creates an HTML file ("!!!!!readme!!!!!.html"), placing it in each folder containing encrypted files.

The pop-up and HTML files contain an identical ransom-demand message stating that files are encrypted, and encouraging victims to visit a Tor website. The website contains a message stating that a ransom of 1 Bitcoin (currently, 1 Bitcoin is equivalent to ~$735) must be paid. Victims will then supposedly be provided with a private key used to decrypt their files. The payment must be submitted with five days, otherwise decryption keys are deleted permanently. Be aware that files encrypted using asymmetric cryptography can only be restored using a private key. Criminals store this key on a remote server and attempt to trick victims into paying for it. Be aware, however, that cyber criminals often ignore victims, despite submitted payments. Therefore, you are strongly advised to ignore all requests to pay. It is highly probable that paying will not deliver any positive result  and you will simply be scammed. Furthermore, you will support their malicious businesses. Unfortunately, there are no tools capable of restoring files encrypted by ASN1 ransomware. Therefore, you can only restore your files/system from a backup.

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

ASN1 decrypt instructions

Updated ASN1 ransomware pop-up message:

asn1 ransomware updated pop-up

ASN1 shares similarities with dozens of other ransomware-type viruses such as *.zzzzz, Shade, Locky, etc. All encrypt files and make ransom demands. There are just two noticeable differences: 1) type of cryptography (symmetric/asymmetric) used, and; 2) cost of decryption. Ransomware is often distributed via third party software download sources (torrents, freeware download websites, free file hosting websites, etc.), infectious files attached to spam emails, fake software update tools, and trojans. Therefore, never download software from unofficial sources or open files received from suspicious/unrecognizable email addresses. Cyber criminals are capable of exploiting software bugs/flaws to infect the system - for this reason, keep your installed applications up-to-date and use a legitimate anti-virus/anti-spyware suite. The key to computer safety is caution.

Screenshot of ASN1 HTML file:

ASN1 decrypt instructions

Text presented within ASN1 pop-up and HTML file:

ALL YOUR FILES WERE ENCRYPTED!
1. Download and install TOR browser (recommended) or use your standard browser.
2. Follow the link that was generated for you.
3. On the next page you will see a Bitcoin wallet to pay, after you pay, you will get the key for decrypting your files.
4. Highlight (CTRL + A) and copy (CTRL + C) the key in clipboard, decoding will start.
5. Please, do not open files during decryption - opened files can not be decrypted.

Updated ASN1 .html ransom demanding file:

asn1 ransomware updated html file

Text presented in this file:

Your computer is under attack. Each file has been encrypted. In order to restore them, please read the following instruction.
What do you need to know?
. You can not restore the files by yourself without our assistance. 1024 bit encryption key has been used. All files encrypted with TripleDES algorithm.
. We guarantee complete recovery. To prove it, you can choose any file in your computer and we can easily decrypt it.
. An interference into the process will lead to the data loss. We highly recommend you not to open the important files and we can not be held responsible for them.
What are you supposed to do in order to decrypt the system?
1. Download and install the TOR browser. The link can be obtained by clicking on the button "COPY LINK(Download TOR browser)".
t will take about 5 minutes to install it as any other browser.
2. Open the personal page in the TOR browser.
ou can get the link by clicking on the button "COPY LINK(Personal Link)".
3. On the personal page you can see an unique BitCoin wallet and the amount you are supposed to deposit.
itCoin is popular e-currency. There are more than 100 different ways you can buy BitCoin .
4. Deposit the required amount to BitCoin wallet.
nce payment is received and confirmed, your private key will appear on the page.
5. Copy paste the private key. Decoding process will start automatically.
elect the private key and then press "CTRL + C".
6. On the personal page you can ask for help in customer service.
ATTENTION!
or decryption our application must be running. If you do not see this text, so antivirus removed the application. Download and install it again on the personal page.
make sure to save the link for your personal page.
PERSONAL PAGE

Screenshot of ASN1 website:

ASN1 decrypt instructions

Text presented within ASN1 website:

Your files were encrypted!
1(0) BTC -> 1QBrNs96QUFXaU22SJh77RSVQkdqyxwBDb (4:23:59:49)
For getting decryption key you must to pay amount, written above, to bitcoin address, written above. Amount in brackets indicates already paid amount. For buy bitcoin online, google it now. This page will refreshed every 120 seconds. If you already paid, please, wait for page refreshing.
If sofware was deleted, download it now . Absense of payment during next five days will double amount.
Chat with support now

Updated Tor website:

asn1 ransomware updated tor website

Text presented in this site:

Personal page
Remaining time is: 1:23:54:33 (after the time is expired, the required amount will be increased in 2 times)
The bitcoins left to be paid: 0.5 BTC
The wallet for the payment: 1BWxxj3QBZVpsXGuwY5ScnCkY5idTsXfop
ANY ATTEMPT TO REMOVE OR DAMAGE THIS CRYPTOLOCKER will lead to the loss of the private key and to the loss of your files.
To make sure that the files can be decrypted, you can decrypt any of the encrypted files for free.
To decrypt the file, follow the link Chat with support.
In the opened window click the Browse button, select the file to decrypt and click Send.
When you upload the page again, you will receive the link for downloading the decrypted file.
Download cryptolocker
Chat with support

Screenshot of files encrypted by ASN1:

ASN1 decrypt instructions

ASN1 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:
▼ DOWNLOAD Malwarebytes By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. To use full-featured product, you have to purchase a license for Malwarebytes. 14 days free trial available.

Quick menu:

Isolating the infected device:

Some ransomware-type infections are designed to encrypt files within external storage devices, infect them, and even spread throughout the entire local network. For this reason, it is very important to isolate the infected device (computer) as soon as possible.

Step 1: Disconnect from the internet.

The easiest way to disconnect a computer from the internet is to unplug the Ethernet cable from the motherboard, however, some devices are connected via a wireless network and for some users (especially those who are not particularly tech-savvy), disconnecting cables may seem troublesome. Therefore, you can also disconnect the system manually via Control Panel:

Navigate to the "Control Panel", click the search bar in the upper-right corner of the screen, enter "Network and Sharing Center" and select search result: Disconnecting computer from the Internet (step 1)

Click the "Change adapter settings" option in the upper-left corner of the window: Disconnecting computer from the Internet (step 2)

Right-click on each connection point and select "Disable". Once disabled, the system will no longer be connected to the internet. To re-enable the connection points, simply right-click again and select "Enable". Disconnecting computer from the Internet (step 3)

Step 2: Unplug all storage devices.

As mentioned above, ransomware might encrypt data and infiltrate all storage devices that are connected to the computer. For this reason, all external storage devices (flash drives, portable hard drives, etc.) should be disconnected immediately, however, we strongly advise you to eject each device before disconnecting to prevent data corruption:

Navigate to "My Computer", right-click on each connected device and select "Eject": Ejecting external storage devices

Step 3: Log-out of cloud storage accounts.

Some ransomware-type might be able to hijack software that handles data stored within "the Cloud". Therefore, the data could be corrupted/encrypted. For this reason, you should log-out of all cloud storage accounts within browsers and other related software. You should also consider temporarily uninstalling the cloud-management software until the infection is completely removed.

Identify the ransomware infection:

To properly handle an infection, one must first identify it. Some ransomware infections use ransom-demand messages as an introduction (see the WALDO ransomware text file below).

Identify ransomware-type infection (step 1)

This, however, is rare. In most cases, ransomware infections deliver more direct messages simply stating that data is encrypted and that victims must pay some sort of ransom. Note that ransomware-type infections typically generate messages with different file names (for example, "_readme.txt", "READ-ME.txt", "DECRYPTION_INSTRUCTIONS.txt", "DECRYPT_FILES.html", etc.). Therefore, using the name of a ransom message may seem like a good way to identify the infection. The problem is that most of these names are generic and some infections use the same names, even though the delivered messages are different and the infections themselves are unrelated. Therefore, using the message filename alone can be ineffective and even lead to permanent data loss (for example, by attempting to decrypt data using tools designed for different ransomware infections, users are likely to end up permanently damaging files and decryption will no longer be possible even with the correct tool).

Another way to identify a ransomware infection is to check the file extension, which is appended to each encrypted file. Ransomware infections are often named by the extensions they append (see files encrypted by Qewe ransomware below).

Identify ransomware-type infection (step 2)

This method is only effective, however, when the appended extension is unique - many ransomware infections append a generic extension (for example, ".encrypted", ".enc", ".crypted", ".locked", etc.). In these cases, identifying ransomware by its appended extension becomes impossible.

One of the easiest and quickest ways to identify a ransomware infection is to use the ID Ransomware website. This service supports most existing ransomware infections. Victims simply upload a ransom message and/or one encrypted file (we advise you to upload both if possible).

Identify ransomware-type infection (step 3)

The ransomware will be identified within seconds and you will be provided with various details, such as the name of the malware family to which the infection belongs, whether it is decryptable, and so on.

Example 1 (Qewe [Stop/Djvu] ransomware):

Identify ransomware-type infection (step 4)

Example 2 (.iso [Phobos] ransomware):

Identify ransomware-type infection (step 5)

If your data happens to be encrypted by a ransomware that is not supported by ID Ransomware, you can always try searching the internet by using certain keywords (for example, ransom message title, file extension, provided contact emails, cryptowallet addresses, etc.).

Search for ransomware decryption tools:

Encryption algorithms used by most ransomware-type infections are extremely sophisticated and, if the encryption is performed properly, only the developer is capable of restoring data. This is because decryption requires a specific key, which is generated during the encryption. Restoring data without the key is impossible. In most cases, cyber criminals store keys on a remote server, rather than using the infected machine as a host. Dharma (CrySis), Phobos, and other families of high-end ransomware infections are virtually flawless, and thus restoring data encrypted without the developers' involvement is simply impossible. Despite this, there are dozens of ransomware-type infections that are poorly developed and contain a number of flaws (for example, the use of identical encryption/decryption keys for each victim, keys stored locally, etc.). Therefore, always check for available decryption tools for any ransomware that infiltrates your computer.

Finding the correct decryption tool on the internet can be very frustrating. For this reason, we recommend that you use the No More Ransom Project and this is where identifying the ransomware infection is useful. The No More Ransom Project website contains a "Decryption Tools" section with a search bar. Enter the name of the identified ransomware, and all available decryptors (if there are any) will be listed.

Searching for ransomware decryption tools in nomoreransom.org website

Restore files with data recovery tools:

Depending on the situation (quality of ransomware infection, type of encryption algorithm used, etc.), restoring data with certain third-party tools might be possible. Therefore, we advise you to use EaseUS Data Recovery Wizard Pro. This tool supports over a thousand data types (graphics, video, audio, documents, etc.) and it is very intuitive (little knowledge is necessary to recover data).

▼ Download
EaseUS Data Recovery Wizard Pro

By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Trial version of EaseUS Data Recovery Wizard Pro is capable of scanning drives and listing recoverable files - to restore them, you must purchase a license.

Step 1: Perform a scan.

Hover your mouse over the partition you wish to scan and select "Scan". You can also select a specific folder, or click shortcut icons to scan the Desktop or Recycle Bin: Scanning the storage drive with EaseUS Data Recovery Wizard PRO (step 1)

Wait for EaseUS Data Recovery Wizard Pro to complete the scan. The scanning duration depends on the volume of files (both in quantity and size) that you are scanning (for example, several hundreds gigabytes could take over an hour to scan). Therefore, be patient during the scanning process. We also advise against modifying or deleting existing files, since this might interfere with the scan. If you add additional data (for example, downloading files/content) while scanning, this will prolong the process: Scanning the storage drive with EaseUS Data Recovery Wizard PRO (step 2)

Step 2: Recover data.

Once the process is complete, select the folders/files you wish to restore and simply click "Recover". Note that some free space on your storage drive is necessary to restore data. Note also that the trial version of EaseUS Data Recovery Wizard Pro is only capable of scanning drives and listing recoverable files - to restore them, you must purchase a license: Recovering data with EaseUS Data Recovery Wizard Pro

Step 3: Save the scan session (optional).

We recommend that you save the scanning session once you have completed recovery, in case you decide to recover additional files later. Simply click the "Save Scan Session" icon in the upper-right corner of the screen and choose the location for the file to be saved. This will save a lot of time, since you will not need to re-scan the storage drive the next time you wish to restore something. Bear in mind, however, that data removed after the scanning session has finished will not be listed: Saving scan session in EaseUS Data Recovery Wizard Pro

Create data backups:

Proper file management and creating backups is essential for data security. Therefore, always be very careful and think ahead.

Partition management: We recommend that you store your data in multiple partitions and avoid storing important files within the partition that contains the entire operating system. If you fall into a situation whereby you cannot boot the system and are forced to format the disk on which the operating system is installed (in most cases, this is where malware infections hide), you will lose all data stored within that drive. This is the advantage of having multiple partitions: if you have the entire storage device assigned to a single partition, you will be forced to delete everything, however, creating multiple partitions and allocating the data properly allows you to prevent such problems. You can easily format a single partition without affecting the others - therefore, one will be cleaned and the others will remain untouched, and your data will be saved. Managing partitions is quite simple and you can find all necessary information on Microsoft's documentation web page.

Data backups: The most reliable backup method is to use an external storage device and keep it unplugged. Copy your data to an external hard drive, flash (thumb) drive, SSD, HDD, or any other storage device, unplug it and store it in a dry place away from sun and extreme temperatures. This method is, however, quite inefficient, since data backups and updates need to be made regularly. You can also use a cloud service or remote server. Here, an internet connection is required and there is always the chance of a security breach. Therefore, you should consider using an application to create data backups locally.

▼ Download
EaseUS Todo Backup

By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. To use full-featured product, you have to purchase a license for EaseUS Todo Backup. 30 days free trial available.

We recommend using the EaseUS Todo Backup application. The "Home" edition of EaseUS Todo Backup is usually more than adequate for regular users, however, the "Business" edition is more suitable for companies and large computer networks. The EaseUS Todo Backup application provides extensive data protection features. You can easily create backups, and encrypt and compress them for enhanced protection and storage saving purposes. It also allows you to set backup schedules, create bootable devices, and restore the system if a crash occurs. You can easily choose where to store the created backup: locally; uploaded to an external drive; FTP; cloud storage, or elsewhere. In summary, EaseUS Todo Backup is an all-in-one tool, which provides all features required to properly backup your data.

Creating a data backup:

The backup process is virtually identical regardless of the item (file, partition, entire system) you wish to backup. Taking the File Backup feature as an example:

Step 1: Choose which item to backup.

Click on the "Menu" icon in the upper-left corner of the screen to reveal the menu and select "File Backup": Creating data backups with EaseUS Todo Backup tool (step 1)

Select the files you want to backup. You can also enter a name and description of the backup that will be created: Creating data backups with EaseUS Todo Backup tool (step 2)

Step 2: Change the default settings.

The EaseUS Todo Backup application provides a variety of additional options that can be added/modified while creating the backup. For example, you can encrypt data (add a password), select the compression rate (how much the backup should be compressed), performance (how many system resources should be allocated), add an email notification (you receive an email once the process is complete) and so on.

To open the options window, click the "Backup options" button in the lower-left corner of the screen: Creating data backups with EaseUS Todo Backup tool (step 3)

Select the settings you want to change and click "Save". You can also reset your changes by clicking "Reset to initial settings": Creating data backups with EaseUS Todo Backup tool (step 4)

Step 3: Select the backup destination.

As mentioned above, EaseUS Todo Backup allows you to choose where backups are saved - locally or externally.

Click the "Browse..." button and select the location you want the backup to be saved: Creating data backups with EaseUS Todo Backup tool (step 5)

Step 4: Safety measures and process completion.

Depending on the location you have chosen, there are a number of measures you should or should not take. If you are uploading to an internet-connected location (for example, Cloud storage, FTP, etc.), be sure to maintain your internet connection, otherwise you will have to start again. The same applies to external storage devices - do not unplug them until the process is complete.

The progress bar displays estimated time remaining until completion. Large backups (hundreds of gigabytes) can take hours to create (depending on storage device speed, internet connection, etc.). Therefore, the application also allows you to optionally choose what the system should do (shut down, sleep or hibernate) once the process has finished: Creating data backups with EaseUS Todo Backup tool (step 6)

The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups.

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 pcrisk.com 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.

Our malware removal guides are free. However, if you want to support us you can send us a donation.

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
asn1 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 asn1 virus on your mobile device.
We Recommend:

Get rid of Windows malware infections today:

▼ REMOVE IT NOW
Download Malwarebytes

Platform: Windows

Editors' Rating for Malwarebytes:
Editors ratingOutstanding!

[Back to Top]

To use full-featured product, you have to purchase a license for Malwarebytes. 14 days free trial available.