How to Stop & Remove Cash Ransomware

The cyber threat landscape has introduced yet another menace, known as Cash Ransomware. This malicious program, developed by the same threat actor behind Cash RAT (Remote Access Trojan) and MintStealer, is designed to encrypt data and demand payment for decryption. Cash Ransomware appends the filenames of encrypted files with a ".CashRansomware" extension, transforming "1.jpg" into "1.jpg.CashRansomware" and "2.png" into "2.png.CashRansomware".

Ransom Note Details

Cash Ransomware creates three ransom notes: a desktop wallpaper, a pop-up window, and an HTML file named "Cash Ransomware.html". These notes, although different in appearance, convey the same critical information:

• Notification that files have been encrypted.
• Demands for a ransom payment to decrypt the data.
• Warnings against actions that could hinder data recovery.

The messages specify that the files were encrypted using XChaCha20, Poly1305, and AES-256-GCM cryptographic algorithms. Victims are instructed to pay 80 USD in Monero (XMR) cryptocurrency for decryption. Additionally, the notes caution against restarting the device or running antivirus programs, as these actions may render the files permanently undecryptable. Disconnecting from the network is also discouraged as it can hinder negotiation and recovery efforts.

The Cash Ransomware note reads like the following:

Cash RANSOMWARE

YOUR FILES
ARE ENCRYPTED
BY CASH RANSOMWARE

What happend?

Dear -, We regret to inform you that your files have been compromised by the insidious Cash Ransomware program. This ruthless malware has infiltrated your system, encrypting your precious data and holding it hostage until its demands are met. Below are the chilling details of this dire situation:

Rapid scanning of your storage drives has been executed, leaving no corner untouched by the malicious claws of Cash Ransomware.
Utilizing the advanced XChaCha20 encryption algorithm, your files have been ensnared with unbreakable tags and a deadly combination of Poly1305 or AES-256-GCM, meticulously chosen by the ransomware's constructors to ensure maximum devastation.
To further fortify its grip on your data, Cash Ransomware employs a hybrid bulletproof encryption technique, rendering any attempts at decryption futile against its impenetrable defenses.
Files bearing specific extensions have been singled out for priority encryption, ensuring that your most critical data is held captive, intensifying the fear and desperation of your predicament.
As a final blow to any hopes of recovery, Cash Ransomware deploys a double-key encryption mechanism, thwarting any attempts at deception or circumvention, leaving you no recourse but to comply with its demands.
In light of this harrowing situation, we implore you to refrain from taking any actions that may exacerbate the damage and worsen your plight:

Do not download antivirus software: Any attempts to combat Cash Ransomware with conventional means will only serve to alert its creators, potentially triggering further encryption or irreversible data loss.
Do not disconnect from the network: Isolation will not shield you from the relentless reach of Cash Ransomware; instead, it may hinder potential avenues of negotiation or resolution.
Do not reboot your systems: Restarting your devices could disrupt ongoing encryption processes, rendering your files irretrievable and sealing your fate in the clutches of this merciless malware.
We understand the gravity of your situation and stand ready to assist you in navigating this crisis. However, time is of the essence, and decisive action is imperative to mitigate the extent of the damage inflicted by Cash Ransomware.

How to decrypt my files?

Your files are heavily encrypted, and none can be decrypted without the decryption key.
To obtain the decryption key, you need to make a payment to the specified amount to the XMR / Monero wallet.
Once you've made the payment, you should contact the attackers via email or Telegram to receive the decryption key.
After receiving the decryption key, you need to input it into the decryption panel in Cash.
Once you hit the decryption button, your files will be decrypted.

Cash Ransomware Analysis

Drawing from extensive experience researching ransomware infections, it is evident that decryption without the attackers' involvement is rarely possible. Paying the ransom does not guarantee data recovery, as cybercriminals often fail to provide the decryption key even after their demands are met. Therefore, it is strongly advised against complying with ransom demands, as it only fuels criminal activities.

Interestingly, the ransom amount demanded by Cash Ransomware is relatively low, which is suspicious. Ransomware typically demands sums ranging from three to four digits (in USD) from home users. When the ransom is unusually low, attackers may not bother sending recovery tools to victims, suggesting the ransomware might be used for revenue generation or testing new software/techniques.

Mitigation and Prevention

To prevent further encryption, Cash Ransomware must be removed from the operating system. However, this will not restore already affected files. Recovery is only possible from a backup, emphasizing the importance of maintaining backups in multiple locations (e.g., remote servers, unplugged storage devices).

Noteworthy Ransomware Examples

LockBit 5, Risen, Cronus, Lynx, and HorrorDead are recent examples of ransomware, all functioning similarly by encrypting data and demanding payment for decryption. Ransomware programs differ primarily in the cryptographic algorithms used (symmetric or asymmetric) and the ransom size, which varies depending on the target (home users vs. large entities like corporations and organizations).

Infection Vectors

Cash Ransomware is offered as RaaS (Ransomware-as-a-Service), meaning its developers sell it to cybercriminals. Consequently, the proliferation method may vary. Generally, malware is spread through phishing and social engineering tactics, often disguised as or bundled with legitimate content. Malicious files can be executables, archives, documents, JavaScript, etc., with the download/installation chain triggered upon opening the infected file.

Common malware distribution techniques include:

• Loader/backdoor-type trojans.
• Drive-by downloads.
• Dubious download sources (e.g., freeware sites, P2P networks).
• Malicious attachments/links in spam mail.
• Online scams.
• Illegal software activation ("cracking") tools.
• Fake updates.

Additionally, some malware can self-spread via local networks and removable storage devices.

Protection Measures

To protect against ransomware infections:

• Download only from official and verified channels.
• Activate and update programs using genuine functions/tools.
• Treat incoming emails and messages with caution.
• Avoid opening suspicious attachments or links.
• Maintain vigilance while browsing to avoid fraudulent content.
• Install and regularly update reputable antivirus software.
• Perform regular system scans to detect and remove threats.

If your computer is infected with Cash Ransomware, it is recommended to run a scan with an anti-malware program to automatically eliminate the threat. Stay safe and keep your data protected by adhering to these best practices.