{ "id": "ff781a6b-0e04-47b2-8644-04cc172eb5ef", "created_at": "2026-04-06T00:15:51.688106Z", "updated_at": "2026-04-10T03:38:20.795169Z", "deleted_at": null, "sha1_hash": "f049c81f4bce9a4ec7e5707f965ce372582c5824", "title": "MAR-10135536-21 – North Korean Tunneling Tool: ELECTRICFISH | CISA", "llm_title": "", "authors": "", "file_creation_date": "0001-01-01T00:00:00Z", "file_modification_date": "0001-01-01T00:00:00Z", "file_size": 56889, "plain_text": "MAR-10135536-21 – North Korean Tunneling Tool: ELECTRICFISH |\r\nCISA\r\nPublished: 2019-05-14 · Archived: 2026-04-05 13:50:25 UTC\r\nNotification\r\nThis report is provided \"as is\" for informational purposes only. The Department of Homeland Security (DHS) does not\r\nprovide any warranties of any kind regarding any information contained herein. The DHS does not endorse any commercial\r\nproduct or service referenced in this bulletin or otherwise.\r\nThis document is marked TLP:WHITE--Disclosure is not limited. Sources may use TLP:WHITE when information carries\r\nminimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to\r\nstandard copyright rules, TLP:WHITE information may be distributed without restriction. For more information on the\r\nTraffic Light Protocol (TLP), see http://www.us-cert.gov/tlp.\r\nSummary\r\nDescription\r\nThis Malware Analysis Report (MAR) is the result of analytic efforts between DHS and the Federal Bureau of Investigation\r\n(FBI). Working with U.S. Government partners, DHS and FBI identified a malware variant used by the North Korean\r\ngovernment. This malware has been identified as ELECTRICFISH. The U.S. Government refers to malicious cyber activity\r\nby the North Korean government as HIDDEN COBRA. For more information on HIDDEN COBRA activity, visit\r\nhttps://www.us-cert.gov/hiddencobra.\r\nDHS and FBI are distributing this MAR to enable network defense and reduce exposure to North Korean government\r\nmalicious cyber activity.\r\nThis MAR includes malware descriptions related to HIDDEN COBRA, suggested response actions and recommended\r\nmitigation techniques. Users or administrators should flag activity associated with the malware and report the activity to the\r\nCybersecurity and Infrastructure Security Agency (CISA) or the FBI Cyber Watch (CyWatch), and give the activity the\r\nhighest priority for enhanced mitigation.\r\nThis report provides analysis of one malicious 32-bit Windows executable file. The malware implements a custom protocol\r\nthat allows traffic to be tunneled between a source and a destination Internet Protocol (IP) address. The malware\r\ncontinuously attempts to reach out to the source and the designation system, which allows either side to initiate a tunneling\r\nsession. The malware can be configured with a proxy server/port and proxy username and password. This feature allows\r\nconnectivity to a system sitting inside of a proxy server, which allows the actor to bypass the compromised system’s\r\nrequired authentication to reach outside of the network.\r\nFor a downloadable copy of IOCs, see:\r\nMAR-10135536-21.stix\r\nSubmitted Files (1)\r\na1260fd3e9221d1bc5b9ece6e7a5a98669c79e124453f2ac58625085759ed3bb (a1260fd3e9221d1bc5b9ece6e7a5a9...)\r\nFindings\r\na1260fd3e9221d1bc5b9ece6e7a5a98669c79e124453f2ac58625085759ed3bb\r\nDetails\r\nName a1260fd3e9221d1bc5b9ece6e7a5a98669c79e124453f2ac58625085759ed3bb\r\nSize 1422336 bytes\r\nType PE32 executable (GUI) Intel 80386, for MS Windows\r\nMD5 8d9123cd2648020292b5c35edc9ae22e\r\nhttps://www.us-cert.gov/ncas/analysis-reports/AR19-129A\r\nPage 1 of 4\n\nSHA1 0939363ff55d914e92635e5f693099fb28047602\r\nSHA256 a1260fd3e9221d1bc5b9ece6e7a5a98669c79e124453f2ac58625085759ed3bb\r\nSHA512 646697e3d5146e05a221183f6c9f00f5eb38400ef9a2f83bfd0fcf2f8af1a7efff99c0a3486740c745ce6cf0939c4f0678cb818cbbff8ed2b28\r\nssdeep 24576:HsO8RKL6OLnWZGFbHq0aMow5Q3gkD/74tU3hYPgP5IyrMsEOhVRpxHkADUHEPbzJ:0KjKHMbO3pkoBIyIstVRpxHL\r\nEntropy 6.703195\r\nAntivirus\r\nBitDefender Gen:Variant.Ursu.349885Unclassified\r\nEmsisoft Gen:Variant.Ursu.349885 (B)\r\nYara Rules\r\nNo matches found.\r\nssdeep Matches\r\nNo matches found.\r\nPE Metadata\r\nCompile Date 2018-09-29 11:55:36-04:00\r\nImport Hash 3549cfa19e60aa9239f79d80e19279fa\r\nPE Sections\r\nMD5 Name Raw Size Entropy\r\n08bb17d8e839e7fc92426e813a696e73 header 1024 2.590786\r\n6c3daca3c522ab98a8ac12a45087297c .text 983040 6.595856\r\n3d3d7962d16652002018640a3fa27d44 .rdata 340480 6.187858\r\nb7f382ea7e6c9c8e737cb92551341e64 .data 37888 4.714377\r\n871fb8486e5ea3307ff7b65ddf46518a .rsrc 512 5.112624\r\n382715f8e776a544bf70f843a52e3ff2 .reloc 59392 6.015022\r\nPackers/Compilers/Cryptors\r\nProcess List\r\nProcess PID PPID\r\nlsass.exe 488 (384)\r\na1260fd3e9221d1bc5b9ece6e7a5a98669c79e124453f2ac58625085759ed3bb.exe 3052 (3024)\r\nDescription\r\nThis file is a malicious Windows 32-bit executable. The application is a command-line utility and its primary purpose is to\r\ntunnel traffic between two IP addresses. The application accepts command-line arguments allowing it to be configured with\r\na destination IP address and port, a source IP address and port, a proxy IP address and port, and a user name and password,\r\nwhich can be utilized to authenticate with a proxy server. It will attempt to establish TCP sessions with the source IP address\r\nand the destination IP address. If a connection is made to both the source and destination IPs, this malicious utility will\r\nimplement a custom protocol, which will allow traffic to rapidly and efficiently be tunneled between two machines. If\r\nhttps://www.us-cert.gov/ncas/analysis-reports/AR19-129A\r\nPage 2 of 4\n\nnecessary, the malware can authenticate with a proxy to be able to reach the destination IP address. A configured proxy\r\nserver is not required for this utility.\r\n--Begin Example Usage--\r\nSource IP/Port: 192.0.2.1:92\r\nDest IP/Port: 198.51.100.1:92\r\nProxy IP/Port: 203.0.113.1:92\r\nProxy User Name: test\r\nProxy Password: testpw\r\na12.exe -s 192.0.2.1:92 -d 198.51.100.1:92 -p 203.0.113.1:92 -u test -pw testpw\r\n--End Example Usage--\r\nAfter the malware authenticates with the configured proxy, it will immediately attempt to establish a session with the\r\ndestination IP address, located outside of the target network and the source IP address. The header of the initial\r\nauthentication packet, sent to both the source and destination systems, will be static except for two random bytes.\r\nEverything within this 34-byte header is static except for the bytes 0X2B6E, which will change during each connection\r\nattempt. Displayed below (and displayed in Figure 7) is the packet header.\r\n--Begin Authentication Packet Sent to Destination System--\r\n6161616162626262636363636464646400000000000000002B6E0000040000009210\r\n--End Authentication Packet Sent to Destination System--\r\nScreenshots\r\nFigure 1 - Screenshot of the malware authenticating with the proxy server configured at command prompt.\r\nFigure 2 - Screenshot of the malware building the authentication packet that will be sent to the destination system. It must\r\nbegin with the static value \"aaaa\" for it to be accepted by the utility.\r\nFigure 3 - Screenshot of the malware evaluating a received authentication packet.\r\nFigure 4 - Screenshot of the malware system authentication packet to the source/destination system.\r\nFigure 5 - Screenshot of the authentication packet sent to the source/destination system during analysis. The malware will\r\nattempt to tunnel traffic between the source and destination systems specified in the command prompt.\r\nFigure 6 - Screenshot of the malware generating two-bytes of random data which will be included in the authentication\r\npacket sent to the source/destination systems.\r\nFigure 7 - Screenshot of the authentication packet sent to \"source\" system with lab environment. Malware will attempt to\r\ntunnel traffic between the source and destination systems specified at command prompt.\r\nRecommendations\r\nCISA recommends that users and administrators consider using the following best practices to strengthen the security\r\nposture of their organization's systems. Any configuration changes should be reviewed by system owners and administrators\r\nprior to implementation to avoid unwanted impacts.\r\nMaintain up-to-date antivirus signatures and engines.\r\nKeep operating system patches up-to-date.\r\nDisable File and Printer sharing services. If these services are required, use strong passwords or Active Directory\r\nauthentication.\r\nRestrict users' ability (permissions) to install and run unwanted software applications. Do not add users to the local\r\nadministrators group unless required.\r\nEnforce a strong password policy and implement regular password changes.\r\nExercise caution when opening e-mail attachments even if the attachment is expected and the sender appears to be\r\nknown.\r\nEnable a personal firewall on agency workstations, configured to deny unsolicited connection requests.\r\nDisable unnecessary services on agency workstations and servers.\r\nScan for and remove suspicious e-mail attachments; ensure the scanned attachment is its \"true file type\" (i.e., the\r\nextension matches the file header).\r\nMonitor users' web browsing habits; restrict access to sites with unfavorable content.\r\nExercise caution when using removable media (e.g., USB thumb drives, external drives, CDs, etc.).\r\nhttps://www.us-cert.gov/ncas/analysis-reports/AR19-129A\r\nPage 3 of 4\n\nScan all software downloaded from the Internet prior to executing.\r\nMaintain situational awareness of the latest threats and implement appropriate Access Control Lists (ACLs).\r\nAdditional information on malware incident prevention and handling can be found in National Institute of Standards and\r\nTechnology (NIST) Special Publication 800-83, \"Guide to Malware Incident Prevention \u0026 Handling for Desktops and\r\nLaptops\".\r\nContact Information\r\nDocument FAQ\r\nWhat is a MIFR? A Malware Initial Findings Report (MIFR) is intended to provide organizations with malware analysis in\r\na timely manner. In most instances this report will provide initial indicators for computer and network defense. To request\r\nadditional analysis, please contact CISA and provide information regarding the level of desired analysis.\r\nWhat is a MAR? A Malware Analysis Report (MAR) is intended to provide organizations with more detailed malware\r\nanalysis acquired via manual reverse engineering. To request additional analysis, please contact CISA and provide\r\ninformation regarding the level of desired analysis.\r\nCan I edit this document? This document is not to be edited in any way by recipients. All comments or questions related to\r\nthis document should be directed to the CISA at 1-844-Say-CISA or contact@mail.cisa.dhs.gov .\r\nCan I submit malware to CISA? Malware samples can be submitted via three methods:\r\nWeb: https://malware.us-cert.gov\r\nE-Mail: submit@malware.us-cert.gov\r\nFTP: ftp.malware.us-cert.gov (anonymous)\r\nCISA encourages you to report any suspicious activity, including cybersecurity incidents, possible malicious code, software\r\nvulnerabilities, and phishing-related scams. Reporting forms can be found on CISA's homepage at www.us-cert.gov.\r\nSource: https://www.us-cert.gov/ncas/analysis-reports/AR19-129A\r\nhttps://www.us-cert.gov/ncas/analysis-reports/AR19-129A\r\nPage 4 of 4", "extraction_quality": 1, "language": "EN", "sources": [ "MISPGALAXY", "Malpedia", "ETDA" ], "references": [ "https://www.us-cert.gov/ncas/analysis-reports/AR19-129A" ], "report_names": [ "AR19-129A" ], "threat_actors": [ { "id": "34eea331-d052-4096-ae03-a22f1d090bd4", "created_at": "2025-08-07T02:03:25.073494Z", "updated_at": "2026-04-10T02:00:03.709243Z", "deleted_at": null, "main_name": "NICKEL ACADEMY", "aliases": [ "ATK3 ", "Black Artemis ", "COVELLITE ", "CTG-2460 ", "Citrine Sleet ", "Diamond Sleet ", "Guardians of Peace", "HIDDEN COBRA ", "High Anonymous", "Labyrinth Chollima ", "Lazarus Group ", "NNPT Group", "New Romanic Cyber Army Team", "Temp.Hermit ", "UNC577 ", "Who Am I?", "Whois Team", "ZINC " ], "source_name": "Secureworks:NICKEL ACADEMY", "tools": [ "Destover", "KorHigh", "Volgmer" ], "source_id": "Secureworks", "reports": null }, { "id": "732597b1-40a8-474c-88cc-eb8a421c29f1", "created_at": "2025-08-07T02:03:25.087732Z", "updated_at": "2026-04-10T02:00:03.776007Z", "deleted_at": null, "main_name": "NICKEL GLADSTONE", "aliases": [ "APT38 ", "ATK 117 ", "Alluring Pisces ", "Black Alicanto ", "Bluenoroff ", "CTG-6459 ", "Citrine Sleet ", "HIDDEN COBRA ", "Lazarus Group", "Sapphire Sleet ", "Selective Pisces ", "Stardust Chollima ", "T-APT-15 ", "TA444 ", "TAG-71 " ], "source_name": "Secureworks:NICKEL GLADSTONE", "tools": [ "AlphaNC", "Bankshot", "CCGC_Proxy", "Ratankba", "RustBucket", "SUGARLOADER", "SwiftLoader", "Wcry" ], "source_id": "Secureworks", "reports": null }, { "id": "a2b92056-9378-4749-926b-7e10c4500dac", "created_at": "2023-01-06T13:46:38.430595Z", "updated_at": "2026-04-10T02:00:02.971571Z", "deleted_at": null, "main_name": "Lazarus Group", "aliases": [ "Operation DarkSeoul", "Bureau 121", "Group 77", "APT38", "NICKEL GLADSTONE", "G0082", "COPERNICIUM", "Moonstone Sleet", "Operation GhostSecret", "APT 38", "Appleworm", "Unit 121", "ATK3", "G0032", "ATK117", "NewRomanic Cyber Army Team", "Nickel Academy", "Sapphire Sleet", "Lazarus group", "Hastati Group", "Subgroup: Bluenoroff", "Operation Troy", "Black Artemis", "Dark Seoul", "Andariel", "Labyrinth Chollima", "Operation AppleJeus", "COVELLITE", "Citrine Sleet", "DEV-0139", "DEV-1222", "Hidden Cobra", "Bluenoroff", "Stardust Chollima", "Whois Hacking Team", "Diamond Sleet", "TA404", "BeagleBoyz", "APT-C-26" ], "source_name": "MISPGALAXY:Lazarus Group", "tools": [], "source_id": "MISPGALAXY", "reports": null }, { "id": "32a223a8-3c79-4146-87c5-8557d38662ae", "created_at": "2022-10-25T15:50:23.703698Z", "updated_at": "2026-04-10T02:00:05.261989Z", "deleted_at": null, "main_name": "Lazarus Group", "aliases": [ "Lazarus Group", "Labyrinth Chollima", "HIDDEN COBRA", "Guardians of Peace", "NICKEL ACADEMY", "Diamond Sleet" ], "source_name": "MITRE:Lazarus Group", "tools": [ "RawDisk", "Proxysvc", "BADCALL", "FALLCHILL", "WannaCry", "MagicRAT", "HOPLIGHT", "TYPEFRAME", "Dtrack", "HotCroissant", "HARDRAIN", "Dacls", "KEYMARBLE", "TAINTEDSCRIBE", "AuditCred", "netsh", "ECCENTRICBANDWAGON", "AppleJeus", "BLINDINGCAN", "ThreatNeedle", "Volgmer", "Cryptoistic", "RATANKBA", "Bankshot" ], "source_id": "MITRE", "reports": null }, { "id": "f32df445-9fb4-4234-99e0-3561f6498e4e", "created_at": "2022-10-25T16:07:23.756373Z", "updated_at": "2026-04-10T02:00:04.739611Z", "deleted_at": null, "main_name": "Lazarus Group", "aliases": [ "APT-C-26", "ATK 3", "Appleworm", "Citrine Sleet", "DEV-0139", "Diamond Sleet", "G0032", "Gleaming Pisces", "Gods Apostles", "Gods Disciples", "Group 77", "Guardians of Peace", "Hastati Group", "Hidden Cobra", "ITG03", "Jade Sleet", "Labyrinth Chollima", "Lazarus Group", "NewRomanic Cyber Army Team", "Operation 99", "Operation AppleJeus", "Operation AppleJeus sequel", "Operation Blockbuster: Breach of Sony Pictures Entertainment", "Operation CryptoCore", "Operation Dream Job", "Operation Dream Magic", "Operation Flame", "Operation GhostSecret", "Operation In(ter)caption", "Operation LolZarus", "Operation Marstech Mayhem", "Operation No Pineapple!", "Operation North Star", "Operation Phantom Circuit", "Operation Sharpshooter", "Operation SyncHole", "Operation Ten Days of Rain / DarkSeoul", "Operation Troy", "SectorA01", "Slow Pisces", "TA404", "TraderTraitor", "UNC2970", "UNC4034", "UNC4736", "UNC4899", "UNC577", "Whois Hacking Team" ], "source_name": "ETDA:Lazarus Group", "tools": [ "3CX Backdoor", "3Rat Client", "3proxy", "AIRDRY", "ARTFULPIE", "ATMDtrack", "AlphaNC", "Alreay", "Andaratm", "AngryRebel", "AppleJeus", "Aryan", "AuditCred", "BADCALL", "BISTROMATH", "BLINDINGCAN", "BTC Changer", "BUFFETLINE", "BanSwift", "Bankshot", "Bitrep", "Bitsran", "BlindToad", "Bookcode", "BootWreck", "BottomLoader", "Brambul", "BravoNC", "Breut", "COLDCAT", "COPPERHEDGE", "CROWDEDFLOUNDER", "Castov", "CheeseTray", "CleanToad", "ClientTraficForwarder", "CollectionRAT", "Concealment Troy", "Contopee", "CookieTime", "Cyruslish", "DAVESHELL", "DBLL Dropper", "DLRAT", "DRATzarus", "DRATzarus RAT", "Dacls", "Dacls RAT", "DarkComet", "DarkKomet", "DeltaCharlie", "DeltaNC", "Dembr", "Destover", "DoublePulsar", "Dozer", "Dtrack", "Duuzer", "DyePack", "ECCENTRICBANDWAGON", "ELECTRICFISH", "Escad", "EternalBlue", "FALLCHILL", "FYNLOS", "FallChill RAT", "Farfli", "Fimlis", "FoggyBrass", "FudModule", "Fynloski", "Gh0st RAT", "Ghost RAT", "Gopuram", "HARDRAIN", "HIDDEN COBRA RAT/Worm", "HLOADER", "HOOKSHOT", "HOPLIGHT", "HOTCROISSANT", "HOTWAX", "HTTP Troy", "Hawup", "Hawup RAT", "Hermes", "HotCroissant", "HotelAlfa", "Hotwax", "HtDnDownLoader", "Http Dr0pper", "ICONICSTEALER", "Joanap", "Jokra", "KANDYKORN", "KEYMARBLE", "Kaos", "KillDisk", "KillMBR", "Koredos", "Krademok", "LIGHTSHIFT", "LIGHTSHOW", "LOLBAS", "LOLBins", "Lazarus", "LightlessCan", "Living off the Land", "MATA", "MBRkiller", "MagicRAT", "Manuscrypt", "Mimail", "Mimikatz", "Moudour", "Mydoom", "Mydoor", "Mytob", "NACHOCHEESE", "NachoCheese", "NestEgg", "NickelLoader", "NineRAT", "Novarg", "NukeSped", "OpBlockBuster", "PCRat", "PEBBLEDASH", "PLANKWALK", "POOLRAT", "PSLogger", "PhanDoor", "Plink", "PondRAT", "PowerBrace", "PowerRatankba", "PowerShell RAT", "PowerSpritz", "PowerTask", "Preft", "ProcDump", "Proxysvc", "PuTTY Link", "QUICKRIDE", "QUICKRIDE.POWER", "Quickcafe", "QuiteRAT", "R-C1", "ROptimizer", "Ratabanka", "RatabankaPOS", "Ratankba", "RatankbaPOS", "RawDisk", "RedShawl", "Rifdoor", "Rising Sun", "Romeo-CoreOne", "RomeoAlfa", "RomeoBravo", "RomeoCharlie", "RomeoCore", "RomeoDelta", "RomeoEcho", "RomeoFoxtrot", "RomeoGolf", "RomeoHotel", "RomeoMike", "RomeoNovember", "RomeoWhiskey", "Romeos", "RustBucket", "SHADYCAT", "SHARPKNOT", "SIGFLIP", "SIMPLESEA", "SLICKSHOES", "SORRYBRUTE", "SUDDENICON", "SUGARLOADER", "SheepRAT", "SierraAlfa", "SierraBravo", "SierraCharlie", "SierraJuliett-MikeOne", "SierraJuliett-MikeTwo", "SimpleTea", "SimplexTea", "SmallTiger", "Stunnel", "TAINTEDSCRIBE", "TAXHAUL", "TFlower", "TOUCHKEY", "TOUCHMOVE", "TOUCHSHIFT", "TOUCHSHOT", "TWOPENCE", "TYPEFRAME", "Tdrop", "Tdrop2", "ThreatNeedle", "Tiger RAT", "TigerRAT", "Trojan Manuscript", "Troy", "TroyRAT", "VEILEDSIGNAL", "VHD", "VHD Ransomware", "VIVACIOUSGIFT", "VSingle", "ValeforBeta", "Volgmer", "Vyveva", "W1_RAT", "Wana Decrypt0r", "WanaCry", "WanaCrypt", "WanaCrypt0r", "WannaCry", "WannaCrypt", "WannaCryptor", "WbBot", "Wcry", "Win32/KillDisk.NBB", "Win32/KillDisk.NBC", "Win32/KillDisk.NBD", "Win32/KillDisk.NBH", "Win32/KillDisk.NBI", "WinorDLL64", "Winsec", "WolfRAT", "Wormhole", "YamaBot", "Yort", "ZetaNile", "concealment_troy", "http_troy", "httpdr0pper", "httpdropper", "klovbot", "sRDI" ], "source_id": "ETDA", "reports": null } ], "ts_created_at": 1775434551, "ts_updated_at": 1775792300, "ts_creation_date": 0, "ts_modification_date": 0, "files": { "pdf": "https://archive.orkl.eu/f049c81f4bce9a4ec7e5707f965ce372582c5824.pdf", "text": "https://archive.orkl.eu/f049c81f4bce9a4ec7e5707f965ce372582c5824.txt", "img": "https://archive.orkl.eu/f049c81f4bce9a4ec7e5707f965ce372582c5824.jpg" } }