What is a Polymorphic Virus? (How to Create, Detect, and Prevent)

Polymorphic Virus

A virus is a program or harmful code that propagates between computers and causes damage to the system. It spreads by copying itself and attaching it to a software file. The viruses merely multiply, show messages, and others may transmit a piece of the dangerous code to a program capable of corrupting applications, deleting files, formatting the hard drive, and destroying vital information.

As the name suggests, a polymorphic code in a computing system is a code that employs a polymorphic engine to modify while preserving the old algorithm unchanged. That is, the code modifies itself all the time it runs. Still, the purpose of the code does not change. Because the code is constantly changing, it gets somewhat complex after numerous attacks, making it more difficult for future attackers. A "shape-shifting" virus or threat generates harmful code that repeats itself indefinitely and alters its properties to dodge and outwit your computer's defenses, eventually sabotaging your system.

How is a Polymorphic Code Created?

Polymorphic code employs a mutation engine in addition to the polymorphic code. From infection to infection, the mutation engine generates a randomly selected decoding routine and adjusts the file name of the polymorphic code.

The virus seeks new programs to infect and adds a duplicate of its body and mutation engine to the new program. This allows the polymorphic virus to propagate and destroy the system without being identified and prevented by any antivirus using the usual signature detection technique.

Working on Polymorphic Code

When an antivirus software detects a virus, it blocks it and any other malicious code with identical features is automatically banned. However, in case of a polymorphic code, even if the signature or decryption procedure changes with each mutation, the virus's core function stays the same.

When the signature and decryption routines change, antivirus software that relies on conventional signature-based detection fails to detect and stop harmful code. As a result, the virus duplicates itself and the mutation engine.

The mutation engine is then activated, and a new decryption method is constructed without relation to the original decryption process. The virus then encrypts its body and mutation engine before attaching the new decoding routine, encrypted virus, and mutation engine to the new program.

How to Detect Polymorphic Codes?

Polymorphic viruses may readily trick traditional antivirus software that relies on signature-based detection. However, emerging security solutions that employ machine learning and behavior detection to recognize any unexpected activity in the system can detect these infections.

There are several measures you can take to improve detection and prevent polymorphic malware from infiltrating your system −

  • Behavior-based detection −This approach examines not just the virus's code but also its behavior which aids in the detection of viruses that exhibit similar behavior. Instead of traditional signature-based detection approaches, use machine learning and behavior-based detection methods.

  • Heuristic Scanning − Instead of seeking a precise match to danger, this method searches for the components that diverse threats share − this aids in the detection of novel viral variants.

  • Install layers of security such as firewalls, antivirus, and anti-malware software.

  • Effective password management procedures require individuals to update their passwords regularly.

Practices to Prevent a Polymorphic Code

Here is a set of precautions that you can take to prevent the spread of a polymorphic code −

  • Maintain software updates. While polymorphic malware may vary its form, the targets are often the same. Most software vendors maintain security upgrades to defend those targets, so it's critical to stay up with any updates on client and server systems.

  • Do not click any suspicious links or attachments. Email is still the main entrance route for fraudsters. Thus it's a golden chance to block polymorphic infestations. In addition to adopting email security solutions, instruct staff to avoid being victim to phishing attempts and avoid clicking on any suspicious links, even if they come from recognized email accounts.

  • Passwords updates. Because lists of common passwords and other data are frequently traded on the dark web, regularly asking employees to update their passwords can help prevent attacks.

  • Make a backup of your data. It cannot be emphasized enough: Make frequent backups of your data. Data backups may help users avoid ransomware threats.

  • Make use of heuristics and behavior detection. A virus infection can be avoided by using security software that is up to date on known polymorphic malware tactics. For example, a heuristic method will avoid virus-like activities, such as encrypting crucial data. Behavior-based detection might warn users of previously undisclosed polymorphic risks based on unexpected access requests.