Home/Threat Actor/Melcoz
Threat Actor

Melcoz

melcoz · latin_america_brazilian_organized_cybercrime · active since 2018

Melcoz (canonical Kaspersky Tetrade framework naming per Securelist July 14, 2020 disclosure by Fabio Assolini "The Tetrade: Brazilian banking malware goes global".

sometimes equated with Mekotio per industry naming dispute reported by CyberScoop + The Hacker News "Researchers with Kaspersky grouped Mekotio also known as Melcoz into a larger group they called Tetrade", naming convention dispute between Kaspersky treating Mekotio = Melcoz Tetrade family member + ESET treating Mekotio as distinct) is a Brazilian-origin banking trojan derived from Remote Access PC open-source RAT lineage, active since at least 2018 (group active in Brazil for years prior to 2018 international expansion)

Brazilian-origin organized cybercrime attribution via Kaspersky Tetrade framework canonical classification alongside Guildma + Javali + Grandoreiro four major Brazilian banking trojan families (curated as Melcoz distinct per Kaspersky 2020 framework + acknowledges Mekotio overlap)

standalone malware platform cluster paralleling javali + mispadu + casbaneiro in v0.1.139 LATAM banking trojan operators cell expansion; operational target profile Brazil + Chile (since 2018 first international target post-Brazil per Kaspersky "the group has attacked assets in Chile since 2018") + Mexico (more recent expansion per Kaspersky 2020) + Spain expansion + Latin America broadly.

operational attack architecture: (1) phishing emails with MSI installer links.

(2) cluster-defining two delivery techniques per Kaspersky, AutoIt loader script + DLL hijacking ("Kaspersky identified two techniques for the malware's delivery, namely an AutoIt loader script and DLL hijacking")

(3) VBS scripts in installer package files per IT Pro.

(4) cluster-defining password theft from memory + browser dual-source ("steals passwords from a user's memory and browser" per Kaspersky + IT Pro)

(5) cluster-defining Bitcoin wallet clipboard replacement hijack tradecraft ("It can also steal a user's Bitcoin wallet and replace the user's wallet information with hacker's banking information" per Kaspersky) cluster-cell coherent with v0.1.133 grandoreiro.yaml crypto wallet replacer + Casbaneiro Bitcoin wallet clipboard tradecraft.

(6) fake banking pop-up overlay GUI input capture typical LATAM banking trojan tradecraft.

(7) cluster-defining Eastern European partner collaboration model per Kaspersky ("Their Eastern European partners heavily inspired the recent attacks. The new operations are professionally executed, scalable and persistent, creating various versions of the malware, with significant infrastructure improvements that enable cybercriminal groups in different countries to collaborate"), signature Brazilian-Eastern-European cybercriminal collaboration model.

(8) cluster-defining Remote Access PC open-source RAT lineage per Kaspersky + SecurityWeek + IT Pro, distinct lineage from typical LATAM banking trojan codebases ("A variant of Remote Access PC, an open-source remote access Trojan")

(9) Delphi programming language origin signature typical LATAM banking trojan codebase.

cluster fills the Remote-Access-PC-RAT-lineage + Bitcoin-wallet- clipboard-hijack + Eastern-European-partner- collaboration position in Latin American banking trojan operators cell + completes Kaspersky Tetrade framework standalone curation (Guildma + Javali + Melcoz + Grandoreiro)

canonical illustration of Kaspersky Tetrade framework member + Remote Access PC RAT open-source lineage + Bitcoin wallet clipboard hijack + Eastern European partner collaboration model tradecraft cited in essentially all subsequent Latin American banking trojan industry analyses through 2018-2026 period.

latin_america_brazilian_organized_cybercrime confidence: high 8 aliases
Sigma rules200 YARA rules0 Live IOCs0 CVEs exploited0

Profile

Melcoz (canonical Kaspersky Tetrade framework naming per July 14, 2020 Securelist disclosure by Fabio Assolini; sometimes equated with Mekotio per Kaspersky industry naming dispute) is a Brazilian- origin banking trojan derived from Remote Access PC open-source RAT lineage, active since at least 2018 with Brazil
  • Chile (2018)
  • Mexico + Spain expansion. Brazilian-origin organized cybercrime attribution via Kaspersky Tetrade framework canonical classification (alongside Guildma + Javali + Grandoreiro). Curated as Melcoz distinct per Kaspersky 2020 framework + acknowledges Mekotio overlap per industry naming dispute. Standalone malware platform cluster paralleling javali + mispadu + casbaneiro in v0.1.139 LATAM banking trojan operators cell expansion.
Operational target profile
  • Brazil + Chile + Mexico + Spain primary targets.
  • Banking + financial institutions primary target category.
  • Bitcoin wallet users secondary target via clipboard replacement.
  • Eastern European partner collaboration model per Kaspersky Operational attack architecture: (1) Phishing emails with MSI installer links (cluster-defining) (2) Two delivery techniques per Kaspersky (cluster- defining):.
  • AutoIt loader script.
  • DLL hijacking (3) VBS scripts in installer package files (signature) (4) Password theft from memory + browser (cluster- defining): dual-source credential collection (5) Bitcoin wallet clipboard replacement hijack (cluster-defining): cryptocurrency wallet information replaced with attacker's per Kaspersky + IT Pro (6) Fake banking pop-up overlay GUI input capture (signature): typical LATAM banking trojan tradecraft (7) Eastern European partner collaboration model (signature): per Kaspersky, professionally executed, scalable, persistent operations with Brazilian-Eastern-European cybercriminal collaboration (8) Remote Access PC RAT open-source variant (cluster-defining lineage): per Kaspersky, distinct lineage from typical LATAM banking trojan codebases (9) Delphi programming language origin (signature) The cluster fills the Remote-Access-PC-RAT-lineage + Bitcoin-wallet-clipboard-hijack + Eastern-European- partner-collaboration position in the Latin American banking trojan operators cell + completes Kaspersky Tetrade framework standalone curation.

Aliases

8
melcozmelcoz_banking_trojanmelcoz_malwaremelcoz tetrade brazilian banking trojanmelcoz kaspersky tetrade membermelcoz brazil chile mexico spain banking trojanmelcoz remote access pc rat variantmelcoz bitcoin wallet clipboard hijack

Notable Campaigns

8
2020-2021Industry Naming Dispute (Mekotio = Melcoz Overlap)
2020Melcoz Mexico Expansion (More Recently, 2020)
2020Kaspersky Tetrade Framework Canonical Classification (July 14, 2020)
2018-2026Continued Industry Reference Status (2018-2026)
2018-2020Melcoz Bitcoin Wallet Clipboard Hijack Signature
2018-2020Melcoz Eastern European Partner Collaboration Model Signature
2018Melcoz Origin, Brazil Active for Years Before 2018 (2018)
2018Melcoz Chile Expansion (2018)

Attribution & Reporting

Attributed by
Kaspersky GReAT (canonical July 14, 2020 Tetrade framework disclosure, Fabio Assolini)Kaspersky Securelist (canonical Tetrade comprehensive analysis)SecurityWeek (canonical Tetrade industry reporting)Threatpost (canonical Brazil's Banking Trojans Go Global reporting)IT Pro (canonical Tetrade family reporting)The Hacker News (canonical 4 Dangerous Brazilian Banking Trojans + Numando reporting referencing Melcoz)SecurityAffairs (canonical Tetrade reporting)Kaspersky LATAM (Dmitry Bestuzhev head of GReAT Latin America)CyberScoop (canonical industry naming dispute reporting, Mekotio = Melcoz consideration)Malpedia Software Profile (Melcoz)
Key reporting
reportKaspersky GReAT (Fabio Assolini): The Tetrade, Brazilian banking malware goes global (July 14, 2020), canonical Tetrade framework disclosure
reportKaspersky LATAM (Dmitry Bestuzhev head of GReAT Latin America): canonical Tetrade press release
reportSecurityWeek: Tetrade Brazilian Banking Trojans Go International (2020)
reportThreatpost: Brazil's Banking Trojans Go Global (July 2020)
reportIT Pro: Researchers detail Tetrade family of Brazilian banking trojans (July 2020)
reportThe Hacker News: 4 Dangerous Brazilian Banking Trojans Now Trying to Rob Users Worldwide (July 2020)
reportSecurityAffairs: Tetrade banking malware families target users worldwide
reportCyberScoop: Mekotio = Melcoz industry naming dispute reporting (2021)
reportMalpedia Software Profile: Melcoz

Operational

State sponsor

Brazilian-origin organized cybercrime, Kaspersky Tetrade framework member alongside Guildma + Javali + Grandoreiro. Operationally separate from state- sponsored APT activity. Attribution chain: (1) Kaspersky Tetrade framework canonical July 2020 classification: per Kaspersky Securelist "The Tetrade: Brazilian banking malware goes global" (Fabio Assolini July 14, 2020). Per Kaspersky: "Melcoz is a banking trojan family developed by a group that has been active in Brazil for years, but at least since 2018, has expanded overseas. Their Eastern European partners heavily inspired the recent attacks. The new operations are professionally executed, scalable and persistent, creating various versions of the malware, with significant infrastructure improvements that enable cybercriminal groups in different countries to collaborate. We found that the group has attacked assets in Chile since 2018 and more recently, in Mexico." (2) Industry naming dispute (Mekotio = Melcoz consideration): per CyberScoop + The Hacker News: "Researchers with Kaspersky grouped Mekotio (also known as 'Melcoz') into a larger group they called Tetrade." Some industry research treats Mekotio + Melcoz as same family.

ESET treats Mekotio as distinct from Kaspersky Tetrade four-family framework. This cluster curated as Melcoz distinct per Kaspersky 2020 framework + acknowledges Mekotio overlap. (3) Industry consensus on Remote Access PC RAT lineage: per SecurityWeek: "The threat is a variant of Remote Access PC, an open-source remote access Trojan, distributed via phishing emails containing links to an MSI installer. Kaspersky identified two techniques for the malware's delivery, namely an AutoIt loader script and DLL hijacking." Operational mission objective: Banking credential theft + Bitcoin wallet theft via clipboard replacement + password theft from memory and browser. Per Kaspersky: "steals passwords from a user's memory and browser. It can also steal a user's Bitcoin wallet and replace the user's wallet information with hacker's banking information.

" Operational target profile
  • Brazil + Chile + Mexico + Spain primary targets per Kaspersky 2018-2020 tracking.
  • Banking + financial institutions primary target category.
  • Bitcoin wallet users secondary target.
  • Eastern European partner collaboration model per Kaspersky The cluster fills the Remote-Access-PC-RAT-lineage + Bitcoin-wallet-clipboard-hijack position in the Latin American banking trojan operators cell + completes Kaspersky Tetrade framework.
Motivations
banking_credential_theft_brazil_chile_mexico_spain_targeting, bitcoin_wallet_clipboard_hijack_capability, remote_access_pc_rat_open_source_lineage_capability, autoit_loader_dll_hijacking_dual_delivery_capability, eastern_european_partner_collaboration_model_capability, kaspersky_tetrade_framework_member_brazilian_cybercrime_capability
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Detection Blind Spots

60 techniques
Across this actor’s 60 mapped techniques, the share covered by each detection layer. Low bars are where you’d be blind if this actor targeted you.
Behavioral / log (Sigma)58/60 · 96%
Analytics (MITRE CAR)26/60 · 43%
Runtime / container (Falco)7/60 · 11%
File / malware (YARA)0/60 · 0%
Network (Suricata/Snort)16/60 · 26%
Vuln scan (Nuclei)0/60 · 0%

Atomic Test Plan

30 techniques
Runnable Atomic Red Team tests covering this actor’s mapped techniques - validate your detections against this specific adversary. Cross-reference the blind spots above. For authorized lab / purple-team use. Open the full builder

Tools Used

0 mapped
Other tooling / TTPs (curation, not ATT&CK-mapped):
MEKOTIO = MELCOZ INDUSTRY NAMING DISPUTEMELCOZ AUTOIT LOADER SCRIPT DELIVERY TECHNIQUEMELCOZ DLL HIJACKING DELIVERY TECHNIQUEMELCOZ REMOTE ACCESS PC RAT OPEN SOURCE VARIANTMELCOZ MALWARE
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