What Is a Crypto Virus & How Does It Work?

Michelle Wilson - February 1, 2022

With crypto virus attacks on the rise, nearly 4,000 attacks occur daily. It’s estimated that nearly $1 billion in ransom is paid to these attacks annually, but the cost of crypto virus attacks extends far beyond money paid out to decrypt files. These viruses result in significant downtime, reputation damage, and data loss for organizations.

What are Crypto Viruses?

The crypto virus is a type of malware that uses a public key. Most often, the public key belongs to the author of the virus, although that’s not always the case. These crypto viruses may use secret sharing to hide communication. By definition, a crypto virus infects a computer using the files, encrypting sets of files and folders. After locking the components, it broadcasts a message demanding a fine, for access to the files. Most crypto viruses are time-sensitive, giving a deadline before all files are ultimately destroyed permanently.

Commonly called the CryptoLocker virus, the crypto virus is ransomware that encrypts files on compromised devices while demanding a ransom for the decryption code. Most often, malware occurs when a user downloads a malicious attachment or link within an email. After a crypto virus has been installed on the victim’s device, large portions of files become encrypted (whether the hard drive, server, or computer).

Common Types of Crypto Viruses

Two notorious crypto viruses include Cryptowall and Locky. Cryptowall is a Trojan horse that first appeared in 2014. It hides within the victim’s operating system, adding itself to the Startup folder. It subsequently deletes volume shadow copies of the compromised files, making it exceptionally difficult to restore the encrypted data. Locky operates as a fraudulent Microsoft Word document, initially appearing in 2014. Within the first week of the attack, more than 400,000 users fell victim to the crypto virus.

CryptoLocker is the most common example of a Crypto Virus attack. It originally emerged in September 2013, pushing through for a few months. CryptoLocker’s design couldn’t multiply on its own, using a botnet to spread. Instead, CryptoLocker attacks occur through unintentional downloads, most often through email downloads. From there, the malware executes, causing an asymmetric encryption method. The CryptoLocker attack hit 500,000 computers worldwide, bringing in an approximate $3 million in paid ransom.

How Do Crypto Viruses Work?

Unlike some crypto viruses, the CryptoLocker doesn’t lock their device entirely. CryptoLocker does, however, prevent the victim from accessing critical files on the system. The malware tells victims to obtain a private key for access in exchange for a fee. Those who fail to accommodate the request will have files permanently. Regardless of your decision, the files are encrypted and become nearly impossible to decrypt.

Paying the ransom doesn’t necessarily guarantee decryption, depending on the criminal’s intent. Some cyber attackers take the payment and disappear, leaving your files inaccessible. It’s imperative to detect such a malicious threat before it infects the system, keeping your files safe and secure.

How to Prevent Getting a Crypto Virus?

Ransomware is a significant threat that renders some devices inoperable. Encrypted files become damaged beyond repair. A few processes can help prepare your system against an attack. These tips can help prevent damage by a crypto virus and limit the overall damage. A firewall can also avoid ransomware attacks by monitoring login activity. This stops brute force attacks and isolates devices when necessary.

• Don’t pirate software online
• Avoid interacting with links you don’t recognize
• Never open suspicious attachments or files
• Always backup your data
• Keep all antivirus and malware protection current
• Choose the full file-extension option on your device to spot suspicious files

Defending Against Crypto Viruses

Unpatched software presents known vulnerabilities for cybercriminal malware. Keeping the operating system and applications up to date can limit your network’s exposure to potential threats. Powerful antivirus solutions are another level of protection against viral threats. A decent antivirus program will protect against APTs, ransomware, and malware.

Keeping your device safe from crypto viruses and ransomware requires in-depth security defenses. Most email-borne threats like crypto viruses have become difficult to detect and are much more sophisticated than original development. Criminals implement fileless techniques to avoid detection, making antivirus software ineffective against some attacks. Windows automatically hides known extensions sent as attachments, which means the file “PDF.EXE” will hide by default. By re-enabling the options to see all hidden file extensions, you’ll be able to manually confirm the attachments (reducing your risk overall).

Common Defenses Against a Crypto Virus

Unfortunately, most antivirus software has fallen behind the modern exploits and advanced security exploits of crypto viruses. Common defense tactics include:

• Using antivirus software to remove the virus often doesn’t ensure the threat is removed.
• Installing malware removal tools to help detect ransomware, deleting it before significant problems occur
• Perform a system restore to an earlier point on the computer, namely a time before you picked up the Crypto virus. This may not decrypt the infected files.
• Reformat the computer’s hard drive to remove the Crypto virus. All applications and files are erased, so ensure you know what you’re doing.

The above methods can help an individual dealing with a singular attack but will often struggle on a network. When the attack impacts many files across multiple servers, it makes it incredibly difficult to undo. Many believe the easiest way to unlock the files is through paying the ransom. While it might sound like a simplified option, it comes with significant risks. It’s never a good idea to send money to the criminal – even if it seems like an easy solution overall. For organizations, holding a secure email against crypto viruses and other dangerous attacks is critical. Implementing multi-layered cloud email security can minimize the risks of an attack.

Most users will try a system restore to remove the crypto virus from the system. Although this occasionally removes the malware from the system, it rarely unlocks the encrypted files. As a final option, reformatting the computer’s hard drive often removes the Crypto Virus. This option is a permanent solution but also wipes all documents and data permanently. This option should be the final choice when all other options are unsuccessful.

Conclusion

The crypto virus is a problematic attack that costs individuals and businesses nearly $1 billion annually. It impacts virtually every component of businesses, causing significant downtime trying to recover files to catastrophic data loss overall. While many affected by ransomware choose to pay the ransom, it isn’t without risk. Some cybercriminals will release the files after receiving the ransom, while others will continue to exploit their victim in hopes of receiving extra funds. Unfortunately, trying to remove the ransomware is often unsuccessful, especially when the attack extends across a server or network.

The easiest approach to crypto viruses is a strong preventative strategy. Making sure your system is patched and secure is the first line of defense. Additionally, using a strong firewall and antivirus program can protect against attacks. Finally, avoid downloading or interacting with unfamiliar links or files, checking the extensions carefully.