SYMBOLCOMMON_NAMEaka. SYNONYMS
win.megacortex (Back to overview)

MegaCortex


Megacortex is a ransomware used in targeted attacks against corporations.
Once the ransomware is run it tries to stop security related services and after that it starts its own encryption process adding a .aes128ctr or .megac0rtx extension to the encrypted files. It is used to be carried from downloaders and trojans, it has no own propagation capabilities.

References
2023-01-05Bleeping ComputerBill Toulas
@online{toulas:20230105:bitdefender:dc76b2a, author = {Bill Toulas}, title = {{Bitdefender releases free MegaCortex ransomware decryptor}}, date = {2023-01-05}, organization = {Bleeping Computer}, url = {https://www.bleepingcomputer.com/news/security/bitdefender-releases-free-megacortex-ransomware-decryptor/}, language = {English}, urldate = {2023-01-06} } Bitdefender releases free MegaCortex ransomware decryptor
MegaCortex
2021-10-29Національна поліція УкраїниНаціональна поліція України
@online{:20211029:cyberpolice:fc43b20, author = {Національна поліція України}, title = {{Cyberpolice exposes transnational criminal group in causing $ 120 million in damage to foreign companies}}, date = {2021-10-29}, organization = {Національна поліція України}, url = {https://www.npu.gov.ua/news/kiberzlochini/kiberpolicziya-vikrila-transnaczionalne-zlochinne-ugrupovannya-u-nanesenni-inozemnim-kompaniyam-120-miljoniv-dolariv-zbitkiv/}, language = {Ukrainian}, urldate = {2021-11-02} } Cyberpolice exposes transnational criminal group in causing $ 120 million in damage to foreign companies
Cobalt Strike Dharma LockerGoga MegaCortex TrickBot
2021-10-29EuropolEuropol
@online{europol:20211029:12:5c0fd59, author = {Europol}, title = {{12 targeted for involvement in ransomware attacks against critical infrastructure}}, date = {2021-10-29}, organization = {Europol}, url = {https://www.europol.europa.eu/newsroom/news/12-targeted-for-involvement-in-ransomware-attacks-against-critical-infrastructure}, language = {English}, urldate = {2021-11-02} } 12 targeted for involvement in ransomware attacks against critical infrastructure
Cobalt Strike Dharma LockerGoga MegaCortex TrickBot
2021-08-15SymantecThreat Hunter Team
@techreport{team:20210815:ransomware:f799696, author = {Threat Hunter Team}, title = {{The Ransomware Threat}}, date = {2021-08-15}, institution = {Symantec}, url = {https://symantec.broadcom.com/hubfs/The_Ransomware_Threat_September_2021.pdf}, language = {English}, urldate = {2021-12-15} } The Ransomware Threat
Babuk BlackMatter DarkSide Avaddon Babuk BADHATCH BazarBackdoor BlackMatter Clop Cobalt Strike Conti DarkSide DoppelPaymer Egregor Emotet FiveHands FriedEx Hades IcedID LockBit Maze MegaCortex MimiKatz QakBot RagnarLocker REvil Ryuk TrickBot WastedLocker
2021-02-02CRONUPGermán Fernández
@online{fernndez:20210202:de:6ff4f3a, author = {Germán Fernández}, title = {{De ataque con Malware a incidente de Ransomware}}, date = {2021-02-02}, organization = {CRONUP}, url = {https://www.cronup.com/post/de-ataque-con-malware-a-incidente-de-ransomware}, language = {Spanish}, urldate = {2021-03-02} } De ataque con Malware a incidente de Ransomware
Avaddon BazarBackdoor Buer Clop Cobalt Strike Conti DanaBot Dharma Dridex Egregor Emotet Empire Downloader FriedEx GootKit IcedID MegaCortex Nemty Phorpiex PwndLocker PyXie QakBot RansomEXX REvil Ryuk SDBbot SmokeLoader TrickBot Zloader
2020-11-27PTSecurityDenis Goydenko, Alexey Vishnyakov
@online{goydenko:20201127:investigation:7d12cee, author = {Denis Goydenko and Alexey Vishnyakov}, title = {{Investigation with a twist: an accidental APT attack and averted data destruction}}, date = {2020-11-27}, organization = {PTSecurity}, url = {https://www.ptsecurity.com/ww-en/analytics/pt-esc-threat-intelligence/incident-response-polar-ransomware-apt27/}, language = {English}, urldate = {2020-12-01} } Investigation with a twist: an accidental APT attack and averted data destruction
TwoFace CHINACHOPPER HyperBro MegaCortex MimiKatz
2020-11-20ZDNetCatalin Cimpanu
@online{cimpanu:20201120:malware:0b8ff59, author = {Catalin Cimpanu}, title = {{The malware that usually installs ransomware and you need to remove right away}}, date = {2020-11-20}, organization = {ZDNet}, url = {https://www.zdnet.com/article/the-malware-that-usually-installs-ransomware-and-you-need-to-remove-right-away/}, language = {English}, urldate = {2020-11-23} } The malware that usually installs ransomware and you need to remove right away
Avaddon BazarBackdoor Buer Clop Cobalt Strike Conti DoppelPaymer Dridex Egregor Emotet FriedEx MegaCortex Phorpiex PwndLocker QakBot Ryuk SDBbot TrickBot Zloader
2020-07-15MandiantNathan Brubaker, Daniel Kapellmann Zafra, Keith Lunden, Ken Proska, Corey Hildebrandt
@online{brubaker:20200715:financially:f217555, author = {Nathan Brubaker and Daniel Kapellmann Zafra and Keith Lunden and Ken Proska and Corey Hildebrandt}, title = {{Financially Motivated Actors Are Expanding Access Into OT: Analysis of Kill Lists That Include OT Processes Used With Seven Malware Families}}, date = {2020-07-15}, organization = {Mandiant}, url = {https://www.mandiant.com/resources/financially-motivated-actors-are-expanding-access-into-ot}, language = {English}, urldate = {2022-07-28} } Financially Motivated Actors Are Expanding Access Into OT: Analysis of Kill Lists That Include OT Processes Used With Seven Malware Families
Clop DoppelPaymer LockerGoga Maze MegaCortex Nefilim Snake
2020-03-05MicrosoftMicrosoft Threat Protection Intelligence Team
@online{team:20200305:humanoperated:d90a28e, author = {Microsoft Threat Protection Intelligence Team}, title = {{Human-operated ransomware attacks: A preventable disaster}}, date = {2020-03-05}, organization = {Microsoft}, url = {https://www.microsoft.com/security/blog/2020/03/05/human-operated-ransomware-attacks-a-preventable-disaster/}, language = {English}, urldate = {2020-03-06} } Human-operated ransomware attacks: A preventable disaster
Dharma DoppelPaymer Dridex EternalPetya Gandcrab Hermes LockerGoga MegaCortex MimiKatz REvil RobinHood Ryuk SamSam TrickBot WannaCryptor PARINACOTA
2020-02-20McAfeeChristiaan Beek, Eamonn Ryan, Darren Fitzpatrick
@online{beek:20200220:csi:8525a7b, author = {Christiaan Beek and Eamonn Ryan and Darren Fitzpatrick}, title = {{CSI: Evidence Indicators for Targeted Ransomware Attacks – Part II}}, date = {2020-02-20}, organization = {McAfee}, url = {https://www.mcafee.com/blogs/other-blogs/mcafee-labs/csi-evidence-indicators-for-targeted-ransomware-attacks-part-ii/}, language = {English}, urldate = {2021-05-13} } CSI: Evidence Indicators for Targeted Ransomware Attacks – Part II
Cobalt Strike LockerGoga Maze MegaCortex
2020-01-29ANSSIANSSI
@techreport{anssi:20200129:tat:3d59e6e, author = {ANSSI}, title = {{État de la menace rançongiciel}}, date = {2020-01-29}, institution = {ANSSI}, url = {https://www.cert.ssi.gouv.fr/uploads/CERTFR-2020-CTI-001.pdf}, language = {English}, urldate = {2020-02-03} } État de la menace rançongiciel
Clop Dharma FriedEx Gandcrab LockerGoga Maze MegaCortex REvil RobinHood Ryuk SamSam
2019-12-24Dev Kundaliya
@online{kundaliya:20191224:warning:6ffa2c8, author = {Dev Kundaliya}, title = {{Warning over LockerGoga and MegaCortex ransomware attacks targeting private industry in western countries}}, date = {2019-12-24}, url = {https://www.computing.co.uk/ctg/news/3084818/warning-over-lockergoga-and-megacortex-ransomware-attacks-targeting-private-industry-in-western-countries}, language = {English}, urldate = {2020-01-06} } Warning over LockerGoga and MegaCortex ransomware attacks targeting private industry in western countries
MegaCortex
2019-12-23Bleeping ComputerLawrence Abrams
@online{abrams:20191223:fbi:7c11cf8, author = {Lawrence Abrams}, title = {{FBI Issues Alert For LockerGoga and MegaCortex Ransomware}}, date = {2019-12-23}, organization = {Bleeping Computer}, url = {https://www.bleepingcomputer.com/news/security/fbi-issues-alert-for-lockergoga-and-megacortex-ransomware/}, language = {English}, urldate = {2020-01-08} } FBI Issues Alert For LockerGoga and MegaCortex Ransomware
LockerGoga MegaCortex
2019-11-05Bleeping ComputerLawrence Abrams
@online{abrams:20191105:new:14b4aaf, author = {Lawrence Abrams}, title = {{New Megacortex Ransomware Changes Windows Passwords, Threatens to Publish Data}}, date = {2019-11-05}, organization = {Bleeping Computer}, url = {https://www.bleepingcomputer.com/news/security/new-megacortex-ransomware-changes-windows-passwords-threatens-to-publish-data/}, language = {English}, urldate = {2020-01-07} } New Megacortex Ransomware Changes Windows Passwords, Threatens to Publish Data
MegaCortex
2019-08-05ThreatpostTara Seals
@online{seals:20190805:megacortex:1cb0c38, author = {Tara Seals}, title = {{MegaCortex Ransomware Revamps for Mass Distribution}}, date = {2019-08-05}, organization = {Threatpost}, url = {https://threatpost.com/megacortex-ransomware-mass-distribution/146933/}, language = {English}, urldate = {2020-01-07} } MegaCortex Ransomware Revamps for Mass Distribution
MegaCortex
2019-07-19Bleeping ComputerLawrence Abrams
@online{abrams:20190719:elusive:153c1b0, author = {Lawrence Abrams}, title = {{Elusive MegaCortex Ransomware Found - Here is What We Know}}, date = {2019-07-19}, organization = {Bleeping Computer}, url = {https://www.bleepingcomputer.com/news/security/elusive-megacortex-ransomware-found-here-is-what-we-know/}, language = {English}, urldate = {2020-01-15} } Elusive MegaCortex Ransomware Found - Here is What We Know
MegaCortex
2019-05-10SophosLabs UncutAndrew Brandt
@online{brandt:20190510:megacortex:6b7c935, author = {Andrew Brandt}, title = {{MegaCortex, deconstructed: mysteries mount as analysis continues}}, date = {2019-05-10}, organization = {SophosLabs Uncut}, url = {https://news.sophos.com/en-us/2019/05/10/megacortex-deconstructed-mysteries-mount-as-analysis-continues/}, language = {English}, urldate = {2022-03-18} } MegaCortex, deconstructed: mysteries mount as analysis continues
MegaCortex
2019-05-07Trend MicroTrendmicro
@online{trendmicro:20190507:megacortex:f7c061d, author = {Trendmicro}, title = {{MegaCortex Ransomware Spotted Attacking Enterprise Networks}}, date = {2019-05-07}, organization = {Trend Micro}, url = {https://www.trendmicro.com/vinfo/pl/security/news/cybercrime-and-digital-threats/megacortex-ransomware-spotted-attacking-enterprise-networks}, language = {English}, urldate = {2020-01-08} } MegaCortex Ransomware Spotted Attacking Enterprise Networks
MegaCortex
2019-05-03SophosAndrew Brandt
@online{brandt:20190503:megacortex:fc2d16b, author = {Andrew Brandt}, title = {{“MegaCortex” ransomware wants to be The One}}, date = {2019-05-03}, organization = {Sophos}, url = {https://news.sophos.com/en-us/2019/05/03/megacortex-ransomware-wants-to-be-the-one/}, language = {English}, urldate = {2019-11-27} } “MegaCortex” ransomware wants to be The One
MegaCortex
2019MalwarebytesMalwarebytes Labs
@online{labs:2019:ransommegacortex:5d35576, author = {Malwarebytes Labs}, title = {{Ransom.Megacortex}}, date = {2019}, organization = {Malwarebytes}, url = {https://blog.malwarebytes.com/detections/ransom-megacortex/}, language = {English}, urldate = {2020-01-10} } Ransom.Megacortex
MegaCortex
Yara Rules
[TLP:WHITE] win_megacortex_auto (20230715 | Detects win.megacortex.)
rule win_megacortex_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.megacortex."
        info = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.6.0"
        signator_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.megacortex"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    /* DISCLAIMER
     * The strings used in this rule have been automatically selected from the
     * disassembly of memory dumps and unpacked files, using YARA-Signator.
     * The code and documentation is published here:
     * https://github.com/fxb-cocacoding/yara-signator
     * As Malpedia is used as data source, please note that for a given
     * number of families, only single samples are documented.
     * This likely impacts the degree of generalization these rules will offer.
     * Take the described generation method also into consideration when you
     * apply the rules in your use cases and assign them confidence levels.
     */


    strings:
        $sequence_0 = { f7d9 1bc9 23c1 8d4aff 8945cc 8d45cc }
            // n = 6, score = 400
            //   f7d9                 | neg                 ecx
            //   1bc9                 | sbb                 ecx, ecx
            //   23c1                 | and                 eax, ecx
            //   8d4aff               | lea                 ecx, [edx - 1]
            //   8945cc               | mov                 dword ptr [ebp - 0x34], eax
            //   8d45cc               | lea                 eax, [ebp - 0x34]

        $sequence_1 = { eb69 56 8d8dfcfcffff e8???????? ff460c 8d8d48fcffff 6a01 }
            // n = 7, score = 400
            //   eb69                 | jmp                 0x6b
            //   56                   | push                esi
            //   8d8dfcfcffff         | lea                 ecx, [ebp - 0x304]
            //   e8????????           |                     
            //   ff460c               | inc                 dword ptr [esi + 0xc]
            //   8d8d48fcffff         | lea                 ecx, [ebp - 0x3b8]
            //   6a01                 | push                1

        $sequence_2 = { f7d9 1bc9 23c8 8bc3 03d1 8d5dd4 0355d8 }
            // n = 7, score = 400
            //   f7d9                 | neg                 ecx
            //   1bc9                 | sbb                 ecx, ecx
            //   23c8                 | and                 ecx, eax
            //   8bc3                 | mov                 eax, ebx
            //   03d1                 | add                 edx, ecx
            //   8d5dd4               | lea                 ebx, [ebp - 0x2c]
            //   0355d8               | add                 edx, dword ptr [ebp - 0x28]

        $sequence_3 = { c645fc01 83fa10 722f 8b8dccfdffff 42 8bc1 81fa00100000 }
            // n = 7, score = 400
            //   c645fc01             | mov                 byte ptr [ebp - 4], 1
            //   83fa10               | cmp                 edx, 0x10
            //   722f                 | jb                  0x31
            //   8b8dccfdffff         | mov                 ecx, dword ptr [ebp - 0x234]
            //   42                   | inc                 edx
            //   8bc1                 | mov                 eax, ecx
            //   81fa00100000         | cmp                 edx, 0x1000

        $sequence_4 = { 2bc6 8b16 83e202 f7d9 1bc9 23c8 51 }
            // n = 7, score = 400
            //   2bc6                 | sub                 eax, esi
            //   8b16                 | mov                 edx, dword ptr [esi]
            //   83e202               | and                 edx, 2
            //   f7d9                 | neg                 ecx
            //   1bc9                 | sbb                 ecx, ecx
            //   23c8                 | and                 ecx, eax
            //   51                   | push                ecx

        $sequence_5 = { e8???????? 83c408 85c0 0f8587010000 8b4514 85ff 7454 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   85c0                 | test                eax, eax
            //   0f8587010000         | jne                 0x18d
            //   8b4514               | mov                 eax, dword ptr [ebp + 0x14]
            //   85ff                 | test                edi, edi
            //   7454                 | je                  0x56

        $sequence_6 = { e9???????? 6a04 b8???????? e8???????? 33db bfff7f0000 895df0 }
            // n = 7, score = 400
            //   e9????????           |                     
            //   6a04                 | push                4
            //   b8????????           |                     
            //   e8????????           |                     
            //   33db                 | xor                 ebx, ebx
            //   bfff7f0000           | mov                 edi, 0x7fff
            //   895df0               | mov                 dword ptr [ebp - 0x10], ebx

        $sequence_7 = { 894204 83790400 7503 895340 6a08 51 }
            // n = 6, score = 400
            //   894204               | mov                 dword ptr [edx + 4], eax
            //   83790400             | cmp                 dword ptr [ecx + 4], 0
            //   7503                 | jne                 5
            //   895340               | mov                 dword ptr [ebx + 0x40], edx
            //   6a08                 | push                8
            //   51                   | push                ecx

        $sequence_8 = { 8975fc 50 e8???????? 83c40c 5f 5e 5b }
            // n = 7, score = 400
            //   8975fc               | mov                 dword ptr [ebp - 4], esi
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx

        $sequence_9 = { e8???????? 8d45f0 3bf0 0f857affffff 8bc3 8b4df4 64890d00000000 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   8d45f0               | lea                 eax, [ebp - 0x10]
            //   3bf0                 | cmp                 esi, eax
            //   0f857affffff         | jne                 0xffffff80
            //   8bc3                 | mov                 eax, ebx
            //   8b4df4               | mov                 ecx, dword ptr [ebp - 0xc]
            //   64890d00000000       | mov                 dword ptr fs:[0], ecx

    condition:
        7 of them and filesize < 1556480
}
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