This is a partial list of notable hacker groups.

• Anonymous, originating in 2003, Anonymous was created as a group for people who fought for the right to privacy.
• Bangladesh Black Hat Hackers, founded in 2012.
• Chaos Computer Club (CCC), founded in 1981, it is Europe's largest association of hackers with 7,700 registered members.
• Conti one of the most prolific ransomware groups of 2021, according to the FBI.^[1]
• Cozy Bear, a Russian hacker group believed to be associated with one or more intelligence agencies of Russia.
• Croatian Revolution Hackers, a now-defunct group of Croatian hackers credited with one of the largest attacks to have occurred in the Balkans.
• Cult of the Dead Cow, also known as cDc or cDc Communications, is a computer hacker and DIY media organization founded in 1984 in Lubbock, Texas.
• Cyber Partisans, a Belarusian hacktivist group that emerged in 2020, that performed attacks on the Belarusian government and governmental agencies.
• DarkSide, a cybercriminal hacking group, believed to be based in Eastern Europe, that targets victims using ransomware and extortion.
• DCLeaks, claims to be a group of "American hacktivists (though indicted individuals were found to be in Russia) who respect and appreciate freedom of speech, human rights and government of the people."
• Decocidio is an anonymous, autonomous collective of hacktivists who are part of Earth First!, a radical environmental protest organization, and adheres to Climate Justice Action.
• Derp, a hacker group that attacked several game sites in late 2013.
• Digital DawgPound (DDP) The DDP was founded and named by StankDawg.
• Equation Group, suspected to be the offensive operations wing of the U.S. National Security Agency.
• Fancy Bear, a Russian cyberespionage group.
• Genocide2600, a group that gained notoriety for combating child pornography. Disbanded in 2009.
• Ghost Squad Hackers, or by the abbreviation "GSH" is a politically motivated hacking team established in 2015.
• Global kOS was a grey hat (leaning black hat) computer hacker group active from 1996 through 2000.
• globalHell was a group of hackers, composed of about 60 individuals. The group disbanded in 1999 when 12 members were prosecuted for computer intrusion and 30 for lesser offenses.
• Goatse Security (GoatSec) is a loose-knit, nine-person grey hat hacker group that specializes in uncovering security flaws.
• Hackweiser is an underground hacking group and hacking magazine founded in 1999.
• Hafnium Possibly with Chinese associations, responsible for the 2021 Microsoft Exchange Server data breach.
• Hive, was a notorious ransomware as a service (RaaS) criminal organization that targeted mainly public institutions.^[2]
• Honker Union is a group known for hacktivism, mainly present in Mainland China, whose members launched a series of attacks on websites in the United States, mostly government-related sites.
• International Subversives was a group of three hackers including Julian Assange under the name Mendax,^{[3][4][5][6][7]} supposedly taken from Horace's splendide mendax (nobly lying)^{[8][9][10][11]} and two others, known as "Trax" and "Prime Suspect" who regularly hacked into corporations like Nortel and systems belonging to a "who’s who of the U.S. military-industrial complex".^[12][13][14]
• Iranian Cyber Army unofficially confirmed to be connected to government.
• IT Army of Ukraine is a volunteer cyberwarfare organisation created amidst the 2022 Russian invasion of Ukraine.
• Killnet is a pro-Russian group that attacked several countries' government institutions and attempted to DDoS the 2022 Eurovision Song Contest website.^[15]
• L0pht, was a hacker collective active between 1992 and 2000 and located in the Boston, Massachusetts area.
• Lapsus$, a black-hat hacker group known for using extortion tactics. active since late 2021, allegedly dumping data from Microsoft, Samsung and Nvidia, and with members arrested in March 2022.
• Lazarus Group, with strong links to the North Korean government, involved in the Sony Pictures hack, the Bangladesh Bank robbery and the WannaCry ransomware attack.
• Legion of Doom; LOD was a hacker group active in the early 80s and mid-90s. Had noted rivalry with Masters of Deception (MOD).
• Legion Hacktivist Group, a hacking group that hijacked the Indian Yahoo server and hacked online news portals of India.
• Level Seven was a hacking group during the mid to late 1990s. Eventually dispersing in early 2000 when their nominal leader "vent" was raided by the FBI on February 25, 2000.
• Lizard Squad, known for their claims of distributed denial-of-service (DDoS) attacks^[16] primarily to disrupt gaming-related services. Currently broken up.
• LulzSec, a group of hackers originating and disbanding in 2011 that claimed to hack "for the lulz".
• Masters of Deception, MOD's initial membership grew from meetings on Loop-Around Test Lines in the early- to mid-1980s. Had noted rivalry with Legion of Doom (LOD).
• Mazafaka, financially motivated group and crime forum.
• milw0rm is a group of "hacktivists" best known for penetrating the computers of the Bhabha Atomic Research Centre (BARC) in Mumbai.
• Mysterious Team Bangladesh, a hacktivist collective found in mid-2020
• NCPH is a Chinese hacker group based out of Zigong in Sichuan Province.
• Noname057(16) a Russian speaking hacker group, attacks aligned with Russia's invasion in Ukraine
• OurMine, a hacker group of unknown origin that has compromised various websites and Twitter accounts as a way of advertising their "professional services".
• P.H.I.R.M., an early hacking group that was founded in the early 1980s.
• Phone Losers of America, an internet prank call community founded in 1994 as a phone phreaking and hacking group.
• Play, a ransomware extortion group, experts believe them to be from Russia.
• Powerful Greek Army, is a Greek group of black-hat computer hackers founded in 2016.
• RedHack is a socialist hacker group based in Turkey, founded in 1997. They usually launch attacks against the Turkish government's websites and leak secret documents of the Turkish government.
• Rhysida group behind the 2023 British Library cyberattack and the Insomniac games dump using ransomware-as-a-service.
• Rocket Kitten or the Rocket Kitten Group is a hacker group thought to be linked to the Iranian government. Formed in 2010 by the hacker personas "Cair3x" and "HUrr!c4nE!".
• Sandworm, also known as Unit 74455, a Russian cyber military unit of the GRU.
• The Shadow Brokers (TSB), originating in summer 2016. They published several leaks containing hacking tools, including several zero-day exploits of the National Security Agency (NSA).
• ShinyHunters is a Hacker Group that is said to be responsible for numerous data breaches in 2020 and 2021.
• TeaMp0isoN is a group of black-hat computer hackers established in mid-2009.
• TeslaTeam is a group of black-hat computer hackers from Serbia established in 2010.
• TESO was a hacker group originating in Austria that was active primarily from 1998 to 2004.
• The Unknowns is a group of white-hat hackers that exploited many high-profiled websites and became very active in 2012 when the group was founded and disbanded.
• Turla one of the most sophisticated groups supporting the Russian government.
• UGNazi, a hacking group led by JoshTheGod, was founded in 2011. They are best known for several attacks on US government sites,^[17] leaking WHMC's database,^[18] DDoS attacks, and exposing personal information of celebrities and other high-profile figures on exposed.su.
• Vice Society, a Russian-speaking hacker group known for attacks on healthcare and education organizations
• Wizard Spider Russian / Ukrainian hacker group, suspected of being behind the Ireland Health Service Executive cyberattack, sometimes called Trickbot per the malware.
• YIPL/TAP - Youth International Party Line or Technological Assistance Program, was an early phone phreak organization and publication created in the 1970s by activists Abbie Hoffman.
• Xbox Underground, an international group responsible for hacking game developers, including Microsoft.
• UNC1151, believed to be based in Belarus.