{
	"id": "9a562123-d41b-46be-9cde-6caf5446b98a",
	"created_at": "2026-04-06T00:06:37.078768Z",
	"updated_at": "2026-04-10T03:21:42.605388Z",
	"deleted_at": null,
	"sha1_hash": "dd884dadbf2ef3dbd2cd0ac1cc2570fe6b640151",
	"title": "MAR-10454006-r2.v1 SEASPY Backdoor | CISA",
	"llm_title": "",
	"authors": "",
	"file_creation_date": "0001-01-01T00:00:00Z",
	"file_modification_date": "0001-01-01T00:00:00Z",
	"file_size": 85337,
	"plain_text": "MAR-10454006-r2.v1 SEASPY Backdoor | CISA\r\nPublished: 2023-07-28 · Archived: 2026-04-05 17:05:44 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:CLEAR--Recipients may share this information without restriction. Sources may use\r\nTLP:CLEAR when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and\r\nprocedures for public release. Subject to standard copyright rules, TLP:CLEAR information may be shared without\r\nrestriction. For more information on the Traffic Light Protocol (TLP), see http://www.cisa.gov/tlp.\r\nSummary\r\nDescription\r\nCISA obtained two SEASPY malware samples. The malware was used by threat actors exploiting CVE-2023-2868, a former\r\nzero-day vulnerability affecting versions 5.1.3.001-9.2.0.006 of Barracuda Email Security Gateway (ESG).\r\nSEASPY is a persistent and passive backdoor that masquerades as a legitimate Barracuda service “BarracudaMailService”\r\nthat allows the threat actors to execute arbitrary commands on the ESG appliance.\r\nFor information about related malware, specifically information on the initial exploit payload and other backdoors, see CISA\r\nAlert: CISA Releases Malware Analysis Reports on Barracuda Backdoors.\r\nDownload the PDF version of this report:\r\nFor a downloadable copy of IOCs associated with this MAR in JSON format, see:\r\nSubmitted Files (2)\r\n3e21e547cf94cb07c010fe82d6965e5bd52dbdd9255b4dd164f64addfaa87abb (BarracudaMailService.1)\r\n69935a1ce0240edf42dbe24535577140601bcf3226fa01e4481682f6de22d192 (6931018-BarracudaMailService.2)\r\nFindings\r\n69935a1ce0240edf42dbe24535577140601bcf3226fa01e4481682f6de22d192\r\nTags\r\ntrojan\r\nDetails\r\n--\u003e\r\nName 6931018-BarracudaMailService.2\r\nSize 2924089 bytes\r\nType\r\nELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, for GNU/Linux 2.6.26,\r\nBuildID[sha1]=495062eaa63784dad0a098d58892f58deb47ea66, with debug_info, not stripped\r\nMD5 5d6cba7909980a7b424b133fbac634ac\r\nSHA1 d114a707fc6abbd8060f821893a9ee64dc3b2714\r\nSHA256 69935a1ce0240edf42dbe24535577140601bcf3226fa01e4481682f6de22d192\r\nSHA512 ef966e1d679daa44ee4c86848b71a0be27a79c8824eba8e74c866322e59a8bdce66b32f3d4417256af351f87dd149a73ed7e8e40df5794c5\r\nssdeep 49152:IaMq45lHsbhe9YBU80A3hvJeD7ANjQ4maMTFhmwzHPm0WhphC:oqJh4YWkLeDKOhmwa0WhphC\r\nhttps://www.cisa.gov/news-events/analysis-reports/ar23-209b\r\nPage 1 of 5\n\nEntropy 6.165718\r\nMalware\r\nResult\r\nunknown\r\nAntivirus\r\nESET a variant of Linux/SeaSpy.A trojan\r\nMcAfee Linux/Seaspy!5D6CBA790998\r\nYARA Rules\r\nrule CISA_10452108_01 : SEASPY backdoor communicates_with_c2 installs_other_components\r\n{\r\n   meta:\r\n       Author = \"CISA Code \u0026 Media Analysis\"\r\n       Incident = \"10452108\"\r\n       Date = \"2023-06-20\"\r\n       Last_Modified = \"20230628_1000\"\r\n       Actor = \"n/a\"\r\n       Family = \"SEASPY\"\r\n       Capabilities = \"communicates-with-c2 installs-other-components\"\r\n       Malware_Type = \"backdoor\"\r\n       Tool_Type = \"unknown\"\r\n       Description = \"Detects malicious Linux SEASPY samples\"\r\n       SHA256_1 = \"3f26a13f023ad0dcd7f2aa4e7771bba74910ee227b4b36ff72edc5f07336f115\"\r\n       SHA256_2 = \"69935a1ce0240edf42dbe24535577140601bcf3226fa01e4481682f6de22d192\"\r\n       SHA256_3 = \"5f5b8cc4d297c8d46a26732ae47c6ac80338b7be97a078a8e1b6eefd1120a5e5\"\r\n       SHA256_4 = \"10efa7fe69e43c189033006010611e84394569571c4f08ea1735073d6433be81\"\r\n   strings:\r\n       $s0 = { 2e 2f 42 61 72 72 61 63 75 64 61 4d 61 69 6c 53 65 72 76 69 63 65 20 65 74 68 30 }\r\n       $s1 = { 75 73 61 67 65 3a 20 2e 2f 42 61 72 72 61 63 75 64 61 4d 61 69 6C 53 65 72 76 69 63 65 20 3c 4e 65 74\r\n77 6f 72 6b 2d 49 6e 74 65 72 66 61 63 65 }\r\n       $s2 = { 65 6e 74 65 72 20 6f 70 65 6e 20 74 74 79 20 73 68 65 6c 6c }\r\n       $s3 = { 25 64 00 4e 4f 20 70 6f 72 74 20 63 6f 64 65 }\r\n       $s4 = { 70 63 61 70 5f 6c 6f 6f 6b 75 70 6e 65 74 3a 20 25 73 }\r\n       $s5 = { 43 68 69 6c 64 20 70 72 6f 63 65 73 73 20 69 64 3a 25 64 }\r\n       $s6 = { 5b 2a 5d 53 75 63 63 65 73 73 21 }\r\n       $a7 = { bf 90 47 90 ec 18 fe e3 83 e2 a9 f7 8d 85 18 1d }\r\n       $a8 = { 81 35 1e f0 94 ab 2a ba 5d f0 37 76 69 19 9f 1e }\r\n       $a9 = { 6a 8e c7 89 ce c1 fe 64 78 a6 e1 c5 fe 03 d1 a7 }\r\n       $a10 = { c2 ff d1 0d 24 23 ec c0 57 f9 8d 4b 05 34 41 b8 }\r\n   condition:\r\n       uint32(0) == 0x464c457f and (all of ($s*)) or ( all of ($a*))\r\n}\r\nssdeep Matches\r\nNo matches found.\r\nDescription\r\nThis artifact is a 64-bit ELF file that has been identified as a \"SEASPY\" malware variant installed as a system service. The\r\nsample is a persistent backdoor that masquerades as a legitimate Barracuda Networks service. The malware is designed to\r\nlisten to commands received from the Threat Actor’s (TA) Command-and-Control (C2) through Transmission Control\r\nProtocol (TCP) packets. When executed, the malware uses libpcap sniffer to monitor traffic for a magic packet on TCP port\r\n25 (SMTP) and TCP port 587. It checks the network packet captured for a hard-coded string \"oXmp\". Note: This hard-coded\r\nstring may change for other SEASPY variants. When the right sequence of packet is captured, it establishes a TCP reverse\r\nshell to the TA's C2 server for further exploitation. This allows the TA to execute arbitrary commands on the compromised\r\nsystem.\r\nhttps://www.cisa.gov/news-events/analysis-reports/ar23-209b\r\nPage 2 of 5\n\nThe malware is based on an open-source backdoor program named \"cd00r\" and it is executed using the parameter below:\r\n--Begin argument—\r\nUsage: \"./BarracudaMailService \u003cNetwork-Interface\u003e\"\r\nSample: \"./\u003cmalware\u003e eth0\"\r\n--End argument—\r\nScreenshots\r\nFigure 1. - This is disassembler output showing how the malware checks the parameters that the malware was executed\r\nwith.\r\n3e21e547cf94cb07c010fe82d6965e5bd52dbdd9255b4dd164f64addfaa87abb\r\nTags\r\ntrojan\r\nDetails\r\n--\u003e\r\nName BarracudaMailService.1\r\nSize 2924089 bytes\r\nType\r\nELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, for GNU/Linux 2.6.26,\r\nBuildID[sha1]=41942e680be29136ce7f1cdc9a15fd43968b0db0, with debug_info, not stripped\r\nMD5 32ffe48d1a8ced49c53033eb65eff6f3\r\nSHA1 2c7ad0e7897f348bec2e32f2af4282bd65916f8d\r\nSHA256 3e21e547cf94cb07c010fe82d6965e5bd52dbdd9255b4dd164f64addfaa87abb\r\nSHA512 12fd230c78c9e14b1bbb7f3c6776a14710693fa4224b4376775f118fc35584a5946a57dda43db20bd9ffc2950f4e62e8c206506744bca5fe3\r\nssdeep 49152:bgt0bmh2EXaRuFmK3cnlBceICm4ewQ/MTs/dgPm0WhphC:Ma0gug7bceI4ih/dp0WhphC\r\nEntropy 6.165197\r\nMalware\r\nResult\r\nunknown\r\nAntivirus\r\nESET a variant of Linux/SeaSpy.A trojan\r\nMcAfee Linux/Seaspy!32FFE48D1A8C\r\nhttps://www.cisa.gov/news-events/analysis-reports/ar23-209b\r\nPage 3 of 5\n\nYARA Rules\r\nrule CISA_10452108_01 : SEASPY backdoor communicates_with_c2 installs_other_components\r\n{\r\n   meta:\r\n       Author = \"CISA Code \u0026 Media Analysis\"\r\n       Incident = \"10452108\"\r\n       Date = \"2023-06-20\"\r\n       Last_Modified = \"20230628_1000\"\r\n       Actor = \"n/a\"\r\n       Family = \"SEASPY\"\r\n       Capabilities = \"communicates-with-c2 installs-other-components\"\r\n       Malware_Type = \"backdoor\"\r\n       Tool_Type = \"unknown\"\r\n       Description = \"Detects malicious Linux SEASPY samples\"\r\n       SHA256_1 = \"3f26a13f023ad0dcd7f2aa4e7771bba74910ee227b4b36ff72edc5f07336f115\"\r\n       SHA256_2 = \"69935a1ce0240edf42dbe24535577140601bcf3226fa01e4481682f6de22d192\"\r\n       SHA256_3 = \"5f5b8cc4d297c8d46a26732ae47c6ac80338b7be97a078a8e1b6eefd1120a5e5\"\r\n       SHA256_4 = \"10efa7fe69e43c189033006010611e84394569571c4f08ea1735073d6433be81\"\r\n   strings:\r\n       $s0 = { 2e 2f 42 61 72 72 61 63 75 64 61 4d 61 69 6c 53 65 72 76 69 63 65 20 65 74 68 30 }\r\n       $s1 = { 75 73 61 67 65 3a 20 2e 2f 42 61 72 72 61 63 75 64 61 4d 61 69 6C 53 65 72 76 69 63 65 20 3c 4e 65 74\r\n77 6f 72 6b 2d 49 6e 74 65 72 66 61 63 65 }\r\n       $s2 = { 65 6e 74 65 72 20 6f 70 65 6e 20 74 74 79 20 73 68 65 6c 6c }\r\n       $s3 = { 25 64 00 4e 4f 20 70 6f 72 74 20 63 6f 64 65 }\r\n       $s4 = { 70 63 61 70 5f 6c 6f 6f 6b 75 70 6e 65 74 3a 20 25 73 }\r\n       $s5 = { 43 68 69 6c 64 20 70 72 6f 63 65 73 73 20 69 64 3a 25 64 }\r\n       $s6 = { 5b 2a 5d 53 75 63 63 65 73 73 21 }\r\n       $a7 = { bf 90 47 90 ec 18 fe e3 83 e2 a9 f7 8d 85 18 1d }\r\n       $a8 = { 81 35 1e f0 94 ab 2a ba 5d f0 37 76 69 19 9f 1e }\r\n       $a9 = { 6a 8e c7 89 ce c1 fe 64 78 a6 e1 c5 fe 03 d1 a7 }\r\n       $a10 = { c2 ff d1 0d 24 23 ec c0 57 f9 8d 4b 05 34 41 b8 }\r\n   condition:\r\n       uint32(0) == 0x464c457f and (all of ($s*)) or ( all of ($a*))\r\n}\r\nssdeep Matches\r\nNo matches found.\r\nDescription\r\nThis artifact is a 64-bit ELF file that has been identified as a \"SEASPY\" malware variant installed as a system service. This\r\nsample has the sample malicious capabilities as BarracudaMailService.2 (5d6cba7909980a7b424b133fbac634ac). The only\r\ndifference between the binaries is located in the function named \"start_pcap_listener\". In the function \"start_pcap_listener\"\r\nboth binaries call a function named \"reverse shell\" to start the reverse shell functionality of the malware. The difference is\r\nthat BarracudaMailService.1 (32ffe48d1a8ced49c53033eb65eff6f3) jumps directly to the set of instructions that start the\r\nreverse shell, as opposed to BarracudaMailService.2 (5d6cba7909980a7b424b133fbac634ac), which contains an extra set of\r\ninstructions before jumping to the instructions that start the reverse shell.\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\nhttps://www.cisa.gov/news-events/analysis-reports/ar23-209b\r\nPage 4 of 5\n\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\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\n1-844-Say-CISA\r\ncontact@mail.cisa.dhs.gov (UNCLASS)\r\nCISA SIPR (SIPRNET)\r\nCISA IC (JWICS)\r\nCISA continuously strives to improve its products and services. You can help by answering a very short series of questions\r\nabout this product at the following URL: https://us-cert.cisa.gov/forms/feedback/\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 SayCISA@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.cisa.gov.\r\nAcknowledgments\r\nMandiant contributed to this report.\r\nSource: https://www.cisa.gov/news-events/analysis-reports/ar23-209b\r\nhttps://www.cisa.gov/news-events/analysis-reports/ar23-209b\r\nPage 5 of 5",
	"extraction_quality": 1,
	"language": "EN",
	"sources": [
		"Malpedia"
	],
	"references": [
		"https://www.cisa.gov/news-events/analysis-reports/ar23-209b"
	],
	"report_names": [
		"ar23-209b"
	],
	"threat_actors": [],
	"ts_created_at": 1775433997,
	"ts_updated_at": 1775791302,
	"ts_creation_date": 0,
	"ts_modification_date": 0,
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