Browse Definitions:
Definition

metamorphic malware

Metamorphic malware is malicious software that is capable of changing its code and signature patterns with each iteration.

At its very simplest, malware contains an encrypted virus that has a decryption routine (VDR) and an encrypted virus body (EVB). When the infected application executes, the VDR decrypts the EVB and the virus carries out its intended function. In the propagation phase, the virus gets re-encrypted and attached to another host application. Each copy generates a new key, but the virus decryption routine remains the same and this is how anti-virus software applications can identify malware programs.

Polymorphic malware adds an additional component to the encrypted code -- a mutation engine (ME) that changes the virus decryption routine with each iteration by using obfuscation techniques such as inserting junk code, reordering instructions and using mathematical contrapositives. This type of malware can still be recognized by anti-virus software fairly easily, however, because the decrypted virus body remains the same.

Metamorphic malware takes virus mutation to the next level. It uses the polymorphic malware’s mutation engine to change both the virus decryption routine and the encrypted virus body. The mutation engine disassembles the code and represents it with a meta-language that characterizes the code’s function but disregards how the code achieves this function. The end result is new code that bears no resemblance to its original syntax, but is functionally the same.

Metamorphic malware is more difficult for anti-virus software to recognize, but not impossible. The weakness of metamorphic software is that the mutation engine needs to analyze the code in order to disassemble it – and if the mutation engine can analyze the code, so can vendors who make anti-virus software. To prevent metamorphic malware from infecting computers on a network, administrators should use a multi-layered approach to blended threat management including:

 

This was last updated in June 2011

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

SearchSecurity

  • Web application firewall (WAF)

    A Web application firewall (WAF) is a firewall that monitors, filters or blocks traffic to and from a Web application. WAFs are ...

  • MD5

    The MD5 hashing algorithm is a one-way cryptographic function that accepts a message of any length as input and returns as output...

  • identity theft

    Identity theft, also known as identity fraud, is a crime in which an imposter obtains key pieces of personally identifiable ...

SearchHealthIT

SearchDisasterRecovery

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

  • mass notification system (MNS)

    A mass notification system is a platform that sends one-way messages to inform employees and the public of an emergency.

  • disaster recovery as a service (DRaaS)

    One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

SearchStorage

  • secondary storage

    Secondary storage is used to protect inactive data written from a primary storage array to a nonvolatile tier of disk, flash or ...

  • VRAM (video ram)

    VRAM (video RAM) is a reference to any type of random access memory (RAM) used to store image data for a computer display.

  • ZFS

    ZFS is a local file system and logical volume manager created by Sun Microsystems to control the placement, storage and retrieval...

SearchSolidStateStorage

  • SSD RAID (solid-state drive RAID)

    SSD RAID (solid-state drive RAID) is a methodology commonly used to protect data by distributing redundant data blocks across ...

  • Tier 0

    Tier 0 (tier zero) is a level of data storage that is faster, and perhaps more expensive, than any other level in the storage ...

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close