Arachna Ransomware: Understanding, Symptoms, Removal, and Prevention

Ransomware is a type of malicious software designed to block access to a system or its data until a ransom is paid. It is one of the most harmful and widespread cybersecurity threats today. This form of malware locks the victim’s files, encrypts them, and demands payment, typically in cryptocurrency like Bitcoin, in exchange for the decryption key. One such ransomware variant is Arachna, which has recently been discovered and analyzed by security researchers.

What is Arachna Ransomware?

Arachna is a type of crypto virus or ransomware that locks files on infected systems and demands a ransom for their decryption. After successful infiltration, it encrypts various files and appends specific extensions to the filenames, making the files unusable without paying the ransom. This ransomware is named Arachna due to the extension it appends to encrypted files: “.Arachna.”

How Arachna Ransomware Works

Installation Methods:

Arachna ransomware typically spreads through infected email attachments, which may contain malicious macros or scripts. It can also spread via torrent websites and malicious advertisements. Once a victim downloads and opens the attachment, the ransomware infiltrates the system and starts its malicious activities.

Actions After Installation:

Upon installation, Arachna begins encrypting files stored on the infected computer. It targets a wide range of file types, including documents, images, and videos. After encryption, the ransomware appends the victim’s unique ID and the cybercriminal’s contact email to the file names. For instance:

• Before encryption: 1.jpg, 2.png
• After encryption: 1.jpg[id-675AD0O7].[Arachna_Recovery@firemail.de].Arachna, 2.png[id-675AD0O7].[Arachna_Recovery@firemail.de].Arachna

These modified files are no longer accessible unless the victim pays the ransom.

Ransom Note Overview

Once Arachna has encrypted the files, it leaves two ransom notes on the infected system. The first note appears as a pop-up window, and the second is saved as a text file named Restore-Files-Guide.txt. These notes explain to the victim that their files have been encrypted due to a “security issue” and provide instructions for how to recover them.

The victim is instructed to email the cybercriminals at arachna_recovery@firemail.de and negotiate the ransom, which is typically paid in Bitcoin. The attackers claim that the ransom price depends on how quickly the victim responds to their demands. They also offer a “free decryption service” for up to two small files (under 1MB) as proof of their ability to decrypt the files. However, they warn victims not to use third-party decryption tools, as doing so could cause permanent data loss.

Consequences of Infection

Arachna’s impact on the victim is severe. All files encrypted by the ransomware become unreadable, and the attacker demands payment to restore access. Even though the cybercriminals promise to send a decryption tool after payment, there is no guarantee that the victim will regain access to their files. Paying the ransom encourages further criminal activity and does not ensure the decryption key will work.

Symptoms of Arachna Ransomware

There are a few key symptoms that indicate Arachna ransomware is present on your system:

• Inability to open files: Files that were previously functional will have a new extension (e.g., filename.Arachna), and attempts to open them will result in an error.
• Presence of ransom notes: A Restore-Files-Guide.txt file or pop-up message with ransom instructions will appear on the desktop.
• Strange file extensions: Encrypted files will have the “.Arachna” extension, indicating the presence of the ransomware.

Detection Names

To identify Arachna ransomware on your system, you can use the following detection names:

• Avast: Win32:MalwareX-gen [Trj]
• Combo Cleaner: Generic.Ransom.DCRTR.7C2E5C28
• Emsisoft: Generic.Ransom.DCRTR.7C2E5C28 (B)
• Lionic: Trojan.Win32.Generic.4!c
• Microsoft: Ransom:Win32/Randet.A!plock

Similar Ransomware Threats

Arachna shares similarities with other ransomware variants such as:

• CryptoLocker
• Locky
• TeslaCrypt

These variants use similar tactics to encrypt files and demand ransoms in Bitcoin or other cryptocurrencies. They can spread via phishing emails, malicious ads, or infected websites.

Detailed Removal Guide

If you find that your system is infected with Arachna ransomware, follow these steps to remove it and prevent further damage:

Step 1: Disconnect from the Internet

Disconnect your computer from the internet to prevent the ransomware from communicating with its command-and-control server and potentially spreading further.

Step 2: Boot in Safe Mode

1. Restart your computer and press F8 or the appropriate key to enter Safe Mode.
2. In Safe Mode, the ransomware will be less active, and you can begin removing it.

Step 3: Run a Full System Scan

1. Download a reliable anti-malware program like SpyHunter and install it.
2. Perform a complete system scan to identify and remove the Arachna ransomware and any other potential threats.

Step 4: Delete Ransom Notes and Encrypted Files

1. Locate and delete the ransom notes (e.g., Restore-Files-Guide.txt) and any files with the “.Arachna” extension.
2. However, be cautious not to delete important files that might still be in use.

Step 5: Restore from Backup

If you have backups of your encrypted files, now is the time to restore them. Ensure that the backup files are clean before restoring them to prevent reinfection.

Step 6: Change Passwords and Enable Security Features

After removing the ransomware, change any passwords associated with your system. Enable advanced security features, like two-factor authentication, to reduce the risk of future attacks.

Prevention Tips

To avoid falling victim to Arachna and other ransomware threats in the future:

1. Use strong, unique passwords for each of your accounts.
2. Avoid opening email attachments from untrusted or unknown sources.
3. Regularly update software to patch any security vulnerabilities.
4. Backup files regularly to ensure data recovery in case of an attack.
5. Use reliable anti-malware software to scan your system and block malicious files.

Protect Your System with SpyHunter

To safeguard your system against Arachna and other types of malware, download SpyHunter. This powerful anti-malware tool can help detect and remove ransomware, trojans, and other threats. You can even scan your computer for free to check for any hidden malware.

Text in This Ransom Note

All your files have been encrypted!
All your files have been encrypted due to a security problem with your PC. If you want to restore them, write us to the e-mail Arachna_Recovery@firemail.de
You have to pay for decryption in Bitcoins. The price depends on how fast you write to us. After payment we will send you the decryption tool that will decrypt all your files. 
Free decryption as guarantee
Before payment you can send us 2 files for free decryption. 
Please note that files must NOT contain valuable information. 
The file size should not exceed 1MB. 
As evidence, we can decrypt one file 
How to obtain Bitcoins
The easiest way to buy bitcoins is LocalBitcoins site. You have to register, click ‘Buy bitcoins’, and select the seller by payment method and price. 
hxxps://localbitcoins.net/buy_bitcoins 
Also you can find other places to buy Bitcoins and beginners guide here: 
hxxp://www.coindesk.com/information/how-can-i-buy-bitcoins/ 
Attention!
Do not rename encrypted files 
Do not try to decrypt your data using third party software, it may cause permanent data loss 
Decryptors of other users are unique and will not fit your files and use of those will result in a loose of data.

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