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
2021-10-29EuropolEuropol
@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
2021-10-29Національна 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
2021-08-15SymantecThreat 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
2020-07-15FireEyeNathan 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 = {FireEye}, url = {https://www.fireeye.com/blog/threat-research/2020/07/financially-motivated-actors-are-expanding-access-into-ot.html}, language = {English}, urldate = {2020-07-16} } Financially Motivated Actors Are Expanding Access Into OT: Analysis of Kill Lists That Include OT Processes Used With Seven Malware Families
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
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 (20220516 | Detects win.megacortex.)
rule win_megacortex_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-05-16"
        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 = "20220513"
        malpedia_hash = "7f4b2229e6ae614d86d74917f6d5b41890e62a26"
        malpedia_version = "20220516"
        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 = { 8d75d8 8d50ff f7da ff75b8 1bd2 2bce }
            // n = 6, score = 400
            //   8d75d8               | lea                 esi, [ebp - 0x28]
            //   8d50ff               | lea                 edx, [eax - 1]
            //   f7da                 | neg                 edx
            //   ff75b8               | push                dword ptr [ebp - 0x48]
            //   1bd2                 | sbb                 edx, edx
            //   2bce                 | sub                 ecx, esi

        $sequence_1 = { e9???????? 6b450c58 ff75e4 034508 50 ff75e0 e8???????? }
            // n = 7, score = 400
            //   e9????????           |                     
            //   6b450c58             | imul                eax, dword ptr [ebp + 0xc], 0x58
            //   ff75e4               | push                dword ptr [ebp - 0x1c]
            //   034508               | add                 eax, dword ptr [ebp + 8]
            //   50                   | push                eax
            //   ff75e0               | push                dword ptr [ebp - 0x20]
            //   e8????????           |                     

        $sequence_2 = { f7da 1bd2 2bcb 23ca 8b55ec 8d1451 03d0 }
            // n = 7, score = 400
            //   f7da                 | neg                 edx
            //   1bd2                 | sbb                 edx, edx
            //   2bcb                 | sub                 ecx, ebx
            //   23ca                 | and                 ecx, edx
            //   8b55ec               | mov                 edx, dword ptr [ebp - 0x14]
            //   8d1451               | lea                 edx, [ecx + edx*2]
            //   03d0                 | add                 edx, eax

        $sequence_3 = { e8???????? 8d45c4 c645fc03 bb01000000 eb2a 8b4504 c745d800000000 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   8d45c4               | lea                 eax, [ebp - 0x3c]
            //   c645fc03             | mov                 byte ptr [ebp - 4], 3
            //   bb01000000           | mov                 ebx, 1
            //   eb2a                 | jmp                 0x2c
            //   8b4504               | mov                 eax, dword ptr [ebp + 4]
            //   c745d800000000       | mov                 dword ptr [ebp - 0x28], 0

        $sequence_4 = { f7da 1bd2 23d0 3bd1 0f8598000000 8a4604 8ac8 }
            // n = 7, score = 400
            //   f7da                 | neg                 edx
            //   1bd2                 | sbb                 edx, edx
            //   23d0                 | and                 edx, eax
            //   3bd1                 | cmp                 edx, ecx
            //   0f8598000000         | jne                 0x9e
            //   8a4604               | mov                 al, byte ptr [esi + 4]
            //   8ac8                 | mov                 cl, al

        $sequence_5 = { e8???????? 8b7df4 8b4304 8b4de8 41 33c1 2b4de0 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   8b7df4               | mov                 edi, dword ptr [ebp - 0xc]
            //   8b4304               | mov                 eax, dword ptr [ebx + 4]
            //   8b4de8               | mov                 ecx, dword ptr [ebp - 0x18]
            //   41                   | inc                 ecx
            //   33c1                 | xor                 eax, ecx
            //   2b4de0               | sub                 ecx, dword ptr [ebp - 0x20]

        $sequence_6 = { 894dfc 7528 8d45fc 50 8d45ec 50 e8???????? }
            // n = 7, score = 400
            //   894dfc               | mov                 dword ptr [ebp - 4], ecx
            //   7528                 | jne                 0x2a
            //   8d45fc               | lea                 eax, [ebp - 4]
            //   50                   | push                eax
            //   8d45ec               | lea                 eax, [ebp - 0x14]
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_7 = { eb1d 83bd0c9dffff10 8d85f89cffff 51 0f4385f89cffff 8bca 50 }
            // n = 7, score = 400
            //   eb1d                 | jmp                 0x1f
            //   83bd0c9dffff10       | cmp                 dword ptr [ebp - 0x62f4], 0x10
            //   8d85f89cffff         | lea                 eax, [ebp - 0x6308]
            //   51                   | push                ecx
            //   0f4385f89cffff       | cmovae              eax, dword ptr [ebp - 0x6308]
            //   8bca                 | mov                 ecx, edx
            //   50                   | push                eax

        $sequence_8 = { e8???????? 83c40c 8d8d2cffffff e8???????? 8d8d44ffffff c645fc2e e8???????? }
            // n = 7, score = 400
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   8d8d2cffffff         | lea                 ecx, [ebp - 0xd4]
            //   e8????????           |                     
            //   8d8d44ffffff         | lea                 ecx, [ebp - 0xbc]
            //   c645fc2e             | mov                 byte ptr [ebp - 4], 0x2e
            //   e8????????           |                     

        $sequence_9 = { 7433 8b4104 8b10 8d3402 4a f7da 1bd2 }
            // n = 7, score = 400
            //   7433                 | je                  0x35
            //   8b4104               | mov                 eax, dword ptr [ecx + 4]
            //   8b10                 | mov                 edx, dword ptr [eax]
            //   8d3402               | lea                 esi, [edx + eax]
            //   4a                   | dec                 edx
            //   f7da                 | neg                 edx
            //   1bd2                 | sbb                 edx, edx

    condition:
        7 of them and filesize < 1556480
}
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