WHAT IS A POLYMORPHIC CODE?
In computing, polymorphic code is a code that uses a polymorphic engine to mutate while keeping the original algorithm intact – that is, the code changes itself every time it runs, but the function of the code will not change at alL.
WHAT IS A POLYMORPHIC VIRUS?
Polymorphic viruses are complex file infectors that can create modified versions of itself to avoid detection yet retain the same basic routines after every infection. To vary their physical file makeup during each infection, polymorphic viruses encrypt their codes and use different encryption keys every time.
Polymorphic viruses rely on mutation engines to alter their decryption routines every time they infect a machine. This way, traditional security solutions may not easily catch them because they do not use a static, unchanging code. The use of complex mutation engines that generate billions of decryption routines make them even more difficult to detect.
Polymorphic viruses are usually distributed via spam, infected sites, or through the use of other malware. URSNIF, VIRLOCK, VOBFUS, and BAGLE or UPolyX are some of the most notorious polymorphic viruses in existence. When combined with other malicious routines, polymorphic viruses pose even greater risk to its victims. In March 2015, researchers found that VIRLOCK evolved to include ransomware routines, making it a challenge to detect and remove.
A polymorphic virus is a harmful, destructive or intrusive type of malware that can change or “morph,” making it difficult to detect with antimalware programs. Evolution of the malicious code can occur in a variety of ways such as filename changes, compression and encryption with variable keys
How polymorphic viruses work
Although the appearance of the code in a polymorphic virus varies with each “mutation,” the essential function usually remains the same. For example, a spyware program intended to act as a keylogger will continue to perform that function even though its signature changes. If the spyware program is discovered by an antimalware program and its signature is added to a downloadable database, the antimalware program will fail to detect the rogue code after the signature changes, just as if a new spyware program has emerged. In this way, malware creators gain an advantage over security vendors that use traditional signature-based detection to find and block malicious code.
How polymorphic code is generated
Polymorphic code typically uses a mutation engine that accompanies the underlying malicious code. The mutation engine doesn’t change the underlying code; instead, the engine generates new decryption routines for the code. The mutation engine can also alter the file names of the polymorphic code. As a result, each time the code is installed on a new device or system, the mutation engine generates a brand new decryption routine.
A polymorphic virus includes an encrypted payload and a mutation engine. The encryption hides the malicious payload from scanners and threat detection software, which are left to identify the virus by its decryption routine. Once the virus is installed on a target, the payload is decrypted and it infects the system; the mutation engine randomly creates a new decryption routine so that when the virus moves to the next target, it appears to be a different file to scanners.
What are the examples of polymorphic virus?
Polymorphic viruses are usually distributed via spam, infected sites, or through the use of other malware. URSNIF, VIRLOCK, VOBFUS, and BAGLE or UPolyX are some of the most notorious polymorphic viruses in existence.
What are the symptoms of polymorphic virus?
A polymorphic virus is a harmful, destructive or intrusive type of malware that can change or “morph,” making it difficult to detect with antimalware programs. Evolution of the malicious code can occur in a variety of ways such as filename changes, compression and encryption with variable keys.
What do polymorphic viruses attempt to achieve?
These viruses repeatedly change their overt characteristics in an attempt to evade and outwit your computer’s defenses and sabotage your system. Polymorphic capabilities are designed to evade signature-based cybersecurity solutions like antivirus and Anti-Malware
What is the difference between metamorphic and polymorphic viruses?
The difference between polymorphic and metamorphic virus is that polymorphic virus encrypts itself using a variable encryption key so that each copy of the virus appears different while metamorphic virus rewrites its code itself, to make each copy of the virus appear different without using a variable encryption key.
How to Prevent the Polymorphic Virus?
- Keep Your Software up to Date.
- Never Click Suspicious Links or Attachments.
- Update Your Defenses.
- Use Heuristic Scanning.
- Use Behavior-based Detection.
- Back up Your Data Regularly.
How to Get Rid of the Polymorphic Virus?
If you have created a system image before your computer is infected with the polymorphic virus, then you can try to run System restore to get rid of the polymorphic virus. But when using this method, you need to be 100% sure that this restore point is not infected with the polymorphic virus.
Follow the simple guide to perform the System Restore:
Step 1: Press the Win + R keys at the same time to open the Run box.
Step 2: Type rstrui in the box and press Enter to open System Restore.
Step 3: Click Next, choose a restore point from the list and then click Next again.
Step 4: Confirm your restore point and then click Finish. Click Yes. Then wait for the process to complete.
Step 5: Reboot your PC to see if the problem is resolved.
If you haven’t created a system restore point, then you should reinstall your Windows system.
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