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
2019-05-07Trend 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 (20211008 | Detects win.megacortex.)
rule win_megacortex_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-10-07"
        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 = "20211007"
        malpedia_hash = "e5b790e0f888f252d49063a1251ca60ec2832535"
        malpedia_version = "20211008"
        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 = { 2bf9 8d75f0 8d4d0c 897de8 2bf1 8975ec 33d2 }
            // n = 7, score = 400
            //   2bf9                 | sub                 edi, ecx
            //   8d75f0               | lea                 esi, dword ptr [ebp - 0x10]
            //   8d4d0c               | lea                 ecx, dword ptr [ebp + 0xc]
            //   897de8               | mov                 dword ptr [ebp - 0x18], edi
            //   2bf1                 | sub                 esi, ecx
            //   8975ec               | mov                 dword ptr [ebp - 0x14], esi
            //   33d2                 | xor                 edx, edx

        $sequence_1 = { 3bc3 0f44d6 8b7208 83c208 2bd7 8d46ff f7d8 }
            // n = 7, score = 400
            //   3bc3                 | cmp                 eax, ebx
            //   0f44d6               | cmove               edx, esi
            //   8b7208               | mov                 esi, dword ptr [edx + 8]
            //   83c208               | add                 edx, 8
            //   2bd7                 | sub                 edx, edi
            //   8d46ff               | lea                 eax, dword ptr [esi - 1]
            //   f7d8                 | neg                 eax

        $sequence_2 = { ff75e0 e8???????? 5f 5e 5b 8be5 5d }
            // n = 7, score = 400
            //   ff75e0               | push                dword ptr [ebp - 0x20]
            //   e8????????           |                     
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp

        $sequence_3 = { e8???????? 46 83ef01 75d4 8b45b4 85c0 7438 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   46                   | inc                 esi
            //   83ef01               | sub                 edi, 1
            //   75d4                 | jne                 0xffffffd6
            //   8b45b4               | mov                 eax, dword ptr [ebp - 0x4c]
            //   85c0                 | test                eax, eax
            //   7438                 | je                  0x3a

        $sequence_4 = { c785e0faffff00000000 c785e4faffff0f000000 8d5101 c685d0faffff00 c78598faffff00000000 c7859cfaffff0f000000 c68588faffff00 }
            // n = 7, score = 400
            //   c785e0faffff00000000     | mov    dword ptr [ebp - 0x520], 0
            //   c785e4faffff0f000000     | mov    dword ptr [ebp - 0x51c], 0xf
            //   8d5101               | lea                 edx, dword ptr [ecx + 1]
            //   c685d0faffff00       | mov                 byte ptr [ebp - 0x530], 0
            //   c78598faffff00000000     | mov    dword ptr [ebp - 0x568], 0
            //   c7859cfaffff0f000000     | mov    dword ptr [ebp - 0x564], 0xf
            //   c68588faffff00       | mov                 byte ptr [ebp - 0x578], 0

        $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 = { ff7608 e8???????? 8b8df8fbffff 83c40c c70601000000 c7460400000000 }
            // n = 6, score = 400
            //   ff7608               | push                dword ptr [esi + 8]
            //   e8????????           |                     
            //   8b8df8fbffff         | mov                 ecx, dword ptr [ebp - 0x408]
            //   83c40c               | add                 esp, 0xc
            //   c70601000000         | mov                 dword ptr [esi], 1
            //   c7460400000000       | mov                 dword ptr [esi + 4], 0

        $sequence_7 = { e8???????? 83c408 c7462800000000 c7462c0f000000 c6461800 5e c3 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   c7462800000000       | mov                 dword ptr [esi + 0x28], 0
            //   c7462c0f000000       | mov                 dword ptr [esi + 0x2c], 0xf
            //   c6461800             | mov                 byte ptr [esi + 0x18], 0
            //   5e                   | pop                 esi
            //   c3                   | ret                 

        $sequence_8 = { 8d75c0 2bce f7df 1bff 23f9 8d72ff 03f8 }
            // n = 7, score = 400
            //   8d75c0               | lea                 esi, dword ptr [ebp - 0x40]
            //   2bce                 | sub                 ecx, esi
            //   f7df                 | neg                 edi
            //   1bff                 | sbb                 edi, edi
            //   23f9                 | and                 edi, ecx
            //   8d72ff               | lea                 esi, dword ptr [edx - 1]
            //   03f8                 | add                 edi, eax

        $sequence_9 = { e8???????? 8d4598 c645fc05 50 8d45d8 83cb0a 50 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   8d4598               | lea                 eax, dword ptr [ebp - 0x68]
            //   c645fc05             | mov                 byte ptr [ebp - 4], 5
            //   50                   | push                eax
            //   8d45d8               | lea                 eax, dword ptr [ebp - 0x28]
            //   83cb0a               | or                  ebx, 0xa
            //   50                   | push                eax

    condition:
        7 of them and filesize < 1556480
}
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