CAT4ER Virus (.CAT4ER Files of Ransomware) — How to remove virus?

The Cat4er virus belongs to the ransomware type of infection. Malware of such sort encrypts all user’s data on the computer (images, text files, excel tables, music, videos, etc) and appends its specific extension to every file, creating the HOW_FIX_FILES.htm text files in every folder with the encrypted files.

What is known about the Cat4ervirus?

☝️ A strictly correct designation for the Cat4er would be “a ransomware-type malicious agent”.

Cat4er adds its specific .Cat4er extension to the title of every encrypted file. For example, a file entitled “photo.jpg” will be changed to “photo.jpg.Cat4er”. Likewise, the Excel file named “table.xlsx” will be altered to “table.xlsx.Cat4er”, and so on.

In every folder containing the encrypted files, a HOW_FIX_FILES.htm text document will appear. It is a ransom money memo. It contains information on the ways of paying the ransom and some other information. The ransom note most probably contains instructions on how to purchase the decryption tool from the tamperers. That is it.

Cat4er summary:

In the screenshot below, you can see what a folder with files encrypted by the Cat4er looks like. Each filename has the “.Cat4er” extension appended to it.

How did my computer get infected with Cat4er ransomware?

There is a huge number of possible ways of ransomware infiltration.

There are currently three most popular methods for hackers to have ransomware settled in your system. These are email spam, Trojan infiltration and peer networks.

If you access your inbox and see emails that look just like notifications from utility services companies, delivery agencies like FedEx, web-access providers, and whatnot, but whose addresser is strange to you, beware of opening those emails. They are most likely to have a ransomware file enclosed in them. So it is even riskier to open any attachments that come with emails like these.

As for the peer-to-peer file transfer protocols like torrent trackers or eMule, the danger is that they are even more trust-based than the rest of the Web. You can never guess what you download until you get it. So you’d better be using trustworthy resources. Also, it is a good idea to scan the directory containing the downloaded items with the antivirus as soon as the downloading is complete.

How to remove the Cat4er virus?

It is crucial to inform you that besides encrypting your data, the Cat4er virus will most likely install the Azorult Spyware on your computer to get access to credentials to different accounts (including cryptocurrency wallets). The mentioned program can extract your credentials from your browser’s auto-filling data.

Often tamperers would decrypt several of your files so you know that they do have the decryption tool. Since Cat4er virus is a relatively recent ransomware, anti-malware engineers have not yet found a method to reverse its work. However, the anti-ransomware instruments are constantly updated, so the effective countermeasure may soon arrive.

Understandably, if the hackers succeed in encoding someone’s essential data, the desperate person will probably comply with their demands. However, paying to racketeers does not necessarily mean that you’re getting your data back. It is still dangerous. After getting the money, the racketeers may send a wrong decryption key to the injured party. There were reports of malefactors simply vanishing after getting the money without even bothering to reply.

The optimal countermeasure to ransomware is to have aan OS restore point or the copies of your essential files in the cloud storage or at least on an external drive. Obviously, that might be not enough. Your most important thing could be that one you were working on when it all went down. But at least it is something. It is also wise to scan your drives with the antivirus program after the system is rolled back.

There are other ransomware products, besides Cat4er, that work similarly. Examples of those are Xcmb, Hudf, Yjqs, and some others. The two main differences between them and the Cat4er are the ransom amount and the encoding method. The rest is the same: files become encrypted, their extensions altered, ransom notes appear in each directory containing encoded files.

Some lucky victims were able to decode the arrested files with the help of the free tools provided by anti-malware specialists. Sometimes the racketeers mistakenly send the decoding code to the victims in the ransom note. Such an epic fail allows the victim to restore the files. But obviously, one should never rely on such a chance. Make no mistake, ransomware is a tamperers’ tool to pull the money out of their victims.

How do I avert ransomware infiltration?

Cat4er ransomware doesn’t have a endless power, neither does any similar malware.

You can defend your computer from its injection taking three easy steps:

• Ignore any letters from unknown senders with strange addresses, or with content that has nothing to do with something you are waiting for (how can you win in a money prize draw without even taking part in it?). In case the email subject is more or less something you are expecting, check all elements of the suspicious email with caution. A fake letter will surely contain mistakes.
• Avoid using cracked or unknown programs. Trojans are often shared as an element of cracked products, most likely under the guise of “patch” to prevent the license check. Understandably, untrusted programs are very hard to tell from reliable software, as trojans sometimes have the functionality you need. You can try searching for information on this program on the anti-malware forums, but the optimal way is not to use such software.

Reasons why I would recommend GridinSoft²

Download Removal Tool.

Run the setup file.

Press “Install” button.

Once installed, Anti-Malware will automatically run.

Wait for the Anti-Malware scan to complete.

Click on “Clean Now”.

Frequently Asked Questions

🤔 How can I open “.Cat4er” files?Can I somehow access “.Cat4er” files?

Unfortunately, no. You need to decipher the “.Cat4er” files first. Then you will be able to open them.

🤔 The encrypted files are very important to me. How can I decrypt them quickly?

If the “.Cat4er” files contain some really important information, then you probably have them backed up. Otherwise, you might try to employ System Restore. The only question is whether you have saved any Restore Points that would be helpful now. There are other ways to beat ransomware, but they take time.

🤔 What actions should I take if the Cat4er ransomware has blocked my PC and I can’t get the activation key.

🤔 What can I do right now?

Many of the encoded files might still be within your reach

• If you sent or received your important files by email, you could still download them from your online mail server.
• You may have shared images or videos with your friends or family members. Simply ask them to send those pictures back to you.
• If you have initially downloaded any of your files from the Internet, you can try doing it again.
• Your messengers, social networks pages, and cloud drives might have all those files too.
• It might be that you still have the needed files on your old computer, a portable device, phone, memory stick, etc.

USEFUL TIP: You can use data recovery utilities⁴ to get your lost data back since ransomware encrypts the copies of your files, deleting the authentic ones. In the video below, you can see how to recover your files with PhotoRec, but remember: you won’t be able to do it before you kill the ransomware itself with an antivirus program.

Also, you can contact the following official fraud and scam sites to report this attack:

• In the United States: On Guard Online;
• In Canada: Canadian Anti-Fraud Centre;
• In the United Kingdom: Action Fraud;
• In Australia: SCAMwatch;
• In New Zealand: Consumer Affairs Scams;
• In France: Agence nationale de la sécurité des systèmes d’information;
• In Germany: Bundesamt für Sicherheit in der Informationstechnik;
• In Ireland: An Garda Síochána;

To report the attack, you can contact local executive boards. For instance, if you live in USA, you can have a talk with FBI Local field office, IC3 or Secret Service.

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