Worm vs. Trojan — What's the Difference?

Malware that spreads across networks by replicating itself.

Appears as legitimate software to deceive users.

Consumes bandwidth and resources.

Needs user action to install.

Moves from system to system without user action.

Often used to steal sensitive information.

Worms are many different distantly related animals that typically have a long cylindrical tube-like body, no limbs, and no eyes. Worms vary in size from microscopic to over 1 metre (3.3 ft) in length for marine polychaete worms (bristle worms), 6.7 metres (22 ft) for the African giant earthworm, Microchaetus rappi, and 58 metres (190 ft) for the marine nemertean worm (bootlace worm), Lineus longissimus.

Can create a backdoor for unauthorized access.

Any of various invertebrates, especially an annelid, flatworm, nematode, or nemertean, having a long, flexible, rounded or flattened body, often without obvious appendages.

Carries harmful actions hidden behind a benign façade.

Any of various crawling insect larvae, such as a grub or a caterpillar, having a soft elongated body.

A native or inhabitant of ancient Troy.

Any of various other animals, such as a shipworm or a slowworm, having a long slender limbless body.

A person of courageous determination or energy.

Something, such as the thread of a screw or the spiral condenser in a still, that resembles a worm in form or appearance.

A celestial body that is in one of the two stable Lagrangian points of a two-body system, especially an asteroid with solar orbits at Jupiter's distance from the sun, but traveling 60° ahead of or behind the planet.

The spirally threaded shaft of a worm gear.

(computing) Malware that appears to perform or actually performs a desired task for a user while performing a harmful task without the user's knowledge or consent.

An insidiously tormenting or devouring force

(astronomy) Describing a satellite (moon or minor planet) that shares an orbit with another

A person regarded as pitiable or contemptible.

To infect (a system) with a trojan.

Worms Medicine Infestation of the intestines or other parts of the body with parasitic worms; helminthiasis.

Of or pertaining to ancient Troy or its inhabitants.

(Computers) A malicious program that replicates itself until it fills all of the storage space on a drive or network.

One who shows the pluck, endurance, determined energy, strength, or the like, attributed to the defenders of Troy; - used chiefly or only in the phrase like a Trojan; as, he endured the pain like a Trojan; he studies like a Trojan.

To make (one's way) with the sinuous crawling motion of a worm.

A native of ancient Troy

To work (one's way or oneself) subtly or gradually; insinuate

A program that appears desirable but actually contains something harmful;

To elicit by artful or devious means. Usually used with out of

Of or relating to the ancient city of Troy or its inhabitants;

To treat for intestinal worms

(Nautical) To wrap yarn or twine spirally around (rope).

To move in a manner suggestive of a worm.

To make one's way by artful or devious means

A generally tubular invertebrate of the annelid phylum; an earthworm.

More loosely, any of various tubular invertebrates resembling annelids but not closely related to them, such as velvet worms, acorn worms, flatworms, or roundworms.

(archaic) A type of wingless "dragon", especially a gigantic sea serpent.

Either a mythical "dragon" (especially wingless), a gigantic sea serpent, or a creature that resembles a Mongolian death worm.

A contemptible or devious being.

(computing) A self-replicating program that propagates through a network.

(cricket) A graphical representation of the total runs scored in an innings.

Anything helical, especially the thread of a screw.

A spiral instrument or screw, often like a double corkscrew, used for drawing balls from firearms.

The spiral wire of a corkscrew.

(anatomy) A muscular band in the tongue of some animals, such as dogs; the lytta.

The condensing tube of a still, often curved and wound to save space.

A short revolving screw whose threads drive, or are driven by, a worm wheel or rack by gearing into its teeth.

(obsolete) Any creeping or crawling animal, such as a snake, snail, or caterpillar.

(figuratively) An internal tormentor; something that gnaws or afflicts one’s mind with remorse.

(math) A strip of linked tiles sharing parallel edges in a tiling.

(anatomy) The lytta.

(preceded by definite article) A dance, or dance move, in which the dancer lies on the floor and undulates the body horizontally thereby moving forwards.

(transitive) To make (one's way) with a crawling motion.

(intransitive) To move with one's body dragging the ground.

To work one's way by artful or devious means.

To work (one's way or oneself) (into) gradually or slowly; to insinuate.

To effect, remove, drive, draw, or the like, by slow and secret means.

To drag out of, to get information that someone is reluctant or unwilling to give (through artful or devious means or by pleading or asking repeatedly).

To fill in the contlines of (a rope) before parcelling and serving.

(transitive) To deworm (an animal).

(transitive) To cut the worm, or lytta, from under the tongue of (a dog, etc.) for the purpose of checking a disposition to gnaw, and formerly supposed to guard against canine madness.

(transitive) To clean by means of a worm; to draw a wad or cartridge from, as a firearm.

A creeping or a crawling animal of any kind or size, as a serpent, caterpillar, snail, or the like.

Any small creeping animal or reptile, either entirely without feet, or with very short ones, including a great variety of animals; as, an earthworm; the blindworm.

An internal tormentor; something that gnaws or afflicts one's mind with remorse.

A being debased and despised.

Anything spiral, vermiculated, or resembling a worm

A spiral instrument or screw, often like a double corkscrew, used for drawing balls from firearms.

To work slowly, gradually, and secretly.

To effect, remove, drive, draw, or the like, by slow and secret means; - often followed by out.

To cut the worm, or lytta, from under the tongue of, as a dog, for the purpose of checking a disposition to gnaw. The operation was formerly supposed to guard against canine madness.

To wind rope, yarn, or other material, spirally round, between the strands of, as a cable; to wind with spun yarn, as a small rope.

Any of numerous relatively small elongated soft-bodied animals especially of the phyla Annelida and Chaetognatha and Nematoda and Nemertea and Platyhelminthes; also many insect larvae

A person who has a nasty or unethical character undeserving of respect

A software program capable of reproducing itself that can spread from one computer to the next over a network;

Screw thread on a gear with the teeth of a worm wheel or rack

To move in a twisting or contorted motion, (especially when struggling);

Uses security flaws to spread.

Can cause significant operational disruptions.

A Trojan horse is malware disguised as legitimate software, tricking users into installing it, often leading to data theft or system compromise.

Worms spread autonomously by exploiting security vulnerabilities in networked systems, without needing user intervention.

Trojans infect systems when users are deceived into executing them, often believing they are installing legitimate software.

Trojans can be harder to detect since they masquerade as legitimate software, requiring careful scrutiny of downloaded files.

A worm is a type of malware that replicates itself to spread across networks, often causing significant damage by overloading systems.

Worms can cause network slowdowns, system crashes, and data loss by replicating rapidly and consuming resources.

Trojans can steal sensitive data, install backdoors, and allow unauthorized access to compromised systems.

No, worms spread autonomously without user interaction by exploiting vulnerabilities in networked systems.

Detection can be challenging as worms spread quickly and exploit vulnerabilities, but antivirus software can often identify them.

No, Trojans disguise themselves as legitimate software and require user execution, whereas viruses embed themselves in files and replicate when those files are executed.

Removal can be complex due to their autonomous spread, but specialized tools and antivirus software can assist in eradication.

Vigilant user practices, avoiding suspicious downloads, and using reliable antivirus software can help prevent Trojan infections.

No, worms are self-replicating and spread autonomously, whereas viruses require a host file and user action to spread.

Trojans can be removed by identifying and deleting the malicious files, often with the help of antivirus software.

Keeping systems updated, using firewalls, and employing robust antivirus solutions can help prevent worm infections.

Yes, Trojans rely on user interaction to be executed and installed, often through deception.