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
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 (20221125 | Detects win.megacortex.)
rule win_megacortex_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-11-21"
        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 = "20221118"
        malpedia_hash = "e0702e2e6d1d00da65c8a29a4ebacd0a4c59e1af"
        malpedia_version = "20221125"
        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 = { 5e 5b 8be5 5d c20c00 ff750c 8b4de4 }
            // n = 7, score = 400
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp
            //   c20c00               | ret                 0xc
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   8b4de4               | mov                 ecx, dword ptr [ebp - 0x1c]

        $sequence_1 = { e8???????? 8bf0 ff35???????? c645fc2c 56 e8???????? 56 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   8bf0                 | mov                 esi, eax
            //   ff35????????         |                     
            //   c645fc2c             | mov                 byte ptr [ebp - 4], 0x2c
            //   56                   | push                esi
            //   e8????????           |                     
            //   56                   | push                esi

        $sequence_2 = { ff15???????? 8b4d10 83c40c 81f980430000 7513 68???????? 57 }
            // n = 7, score = 400
            //   ff15????????         |                     
            //   8b4d10               | mov                 ecx, dword ptr [ebp + 0x10]
            //   83c40c               | add                 esp, 0xc
            //   81f980430000         | cmp                 ecx, 0x4380
            //   7513                 | jne                 0x15
            //   68????????           |                     
            //   57                   | push                edi

        $sequence_3 = { 8d42ff f7d8 1bc0 23c8 8d45dc 03ca 890e }
            // n = 7, score = 400
            //   8d42ff               | lea                 eax, [edx - 1]
            //   f7d8                 | neg                 eax
            //   1bc0                 | sbb                 eax, eax
            //   23c8                 | and                 ecx, eax
            //   8d45dc               | lea                 eax, [ebp - 0x24]
            //   03ca                 | add                 ecx, edx
            //   890e                 | mov                 dword ptr [esi], ecx

        $sequence_4 = { 8d4d0c 2bce 8d42ff f7d8 51 1bc0 23c1 }
            // n = 7, score = 400
            //   8d4d0c               | lea                 ecx, [ebp + 0xc]
            //   2bce                 | sub                 ecx, esi
            //   8d42ff               | lea                 eax, [edx - 1]
            //   f7d8                 | neg                 eax
            //   51                   | push                ecx
            //   1bc0                 | sbb                 eax, eax
            //   23c1                 | and                 eax, ecx

        $sequence_5 = { 8d42ff 897df8 8d4dec c6450f01 2bf1 f7d8 1bc0 }
            // n = 7, score = 400
            //   8d42ff               | lea                 eax, [edx - 1]
            //   897df8               | mov                 dword ptr [ebp - 8], edi
            //   8d4dec               | lea                 ecx, [ebp - 0x14]
            //   c6450f01             | mov                 byte ptr [ebp + 0xf], 1
            //   2bf1                 | sub                 esi, ecx
            //   f7d8                 | neg                 eax
            //   1bc0                 | sbb                 eax, eax

        $sequence_6 = { f7d8 1bc0 23c6 8d3c10 897df0 83ff01 7440 }
            // n = 7, score = 400
            //   f7d8                 | neg                 eax
            //   1bc0                 | sbb                 eax, eax
            //   23c6                 | and                 eax, esi
            //   8d3c10               | lea                 edi, [eax + edx]
            //   897df0               | mov                 dword ptr [ebp - 0x10], edi
            //   83ff01               | cmp                 edi, 1
            //   7440                 | je                  0x42

        $sequence_7 = { e8???????? 8b45b4 46 48 8945b4 85c0 75ce }
            // n = 7, score = 400
            //   e8????????           |                     
            //   8b45b4               | mov                 eax, dword ptr [ebp - 0x4c]
            //   46                   | inc                 esi
            //   48                   | dec                 eax
            //   8945b4               | mov                 dword ptr [ebp - 0x4c], eax
            //   85c0                 | test                eax, eax
            //   75ce                 | jne                 0xffffffd0

        $sequence_8 = { e8???????? ff7608 e8???????? 83c418 8b4510 894604 897e08 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   ff7608               | push                dword ptr [esi + 8]
            //   e8????????           |                     
            //   83c418               | add                 esp, 0x18
            //   8b4510               | mov                 eax, dword ptr [ebp + 0x10]
            //   894604               | mov                 dword ptr [esi + 4], eax
            //   897e08               | mov                 dword ptr [esi + 8], edi

        $sequence_9 = { 6a00 e8???????? eb1d 83ff10 8d85809cffff 52 0f4385809cffff }
            // n = 7, score = 400
            //   6a00                 | push                0
            //   e8????????           |                     
            //   eb1d                 | jmp                 0x1f
            //   83ff10               | cmp                 edi, 0x10
            //   8d85809cffff         | lea                 eax, [ebp - 0x6380]
            //   52                   | push                edx
            //   0f4385809cffff       | cmovae              eax, dword ptr [ebp - 0x6380]

    condition:
        7 of them and filesize < 1556480
}
Download all Yara Rules