SYMBOLCOMMON_NAMEaka. SYNONYMS
win.microbackdoor (Back to overview)

MicroBackdoor

Actor(s): Ghostwriter


Open-source lightweight backdoor for C2 communication.
GitHub: https://github.com/Cr4sh/MicroBackdoor

References
2022-07-20MandiantMandiant Threat Intelligence
@online{intelligence:20220720:evacuation:edd478e, author = {Mandiant Threat Intelligence}, title = {{Evacuation and Humanitarian Documents used to Spear Phish Ukrainian Entities}}, date = {2022-07-20}, organization = {Mandiant}, url = {https://www.mandiant.com/resources/spear-phish-ukrainian-entities}, language = {English}, urldate = {2022-07-25} } Evacuation and Humanitarian Documents used to Spear Phish Ukrainian Entities
Cobalt Strike GraphSteel GrimPlant MicroBackdoor
2022-07-20U.S. Cyber CommandCyber National Mission Force Public Affairs
@online{affairs:20220720:cyber:b7604e7, author = {Cyber National Mission Force Public Affairs}, title = {{Cyber National Mission Force discloses IOCs from Ukrainian networks}}, date = {2022-07-20}, organization = {U.S. Cyber Command}, url = {https://www.cybercom.mil/Media/News/Article/3098856/cyber-national-mission-force-discloses-iocs-from-ukrainian-networks/}, language = {English}, urldate = {2022-07-25} } Cyber National Mission Force discloses IOCs from Ukrainian networks
Cobalt Strike GraphSteel GrimPlant MicroBackdoor
2022-04-29AttackIQFrancis Guibernau, Jackson Wells
@online{guibernau:20220429:attack:52c55b9, author = {Francis Guibernau and Jackson Wells}, title = {{Attack Graph Response to UNC1151 Continued Targeting of Ukraine}}, date = {2022-04-29}, organization = {AttackIQ}, url = {https://attackiq.com/2022/04/29/attack-graph-response-to-unc1151-continued-targeting-of-ukraine/}, language = {English}, urldate = {2022-05-04} } Attack Graph Response to UNC1151 Continued Targeting of Ukraine
MicroBackdoor
2022-04-07InQuestWill MacArthur, Nick Chalard
@online{macarthur:20220407:ukraine:99bef5a, author = {Will MacArthur and Nick Chalard}, title = {{Ukraine CyberWar Overview}}, date = {2022-04-07}, organization = {InQuest}, url = {https://inquest.net/blog/2022/04/07/ukraine-cyberwar-overview}, language = {English}, urldate = {2022-04-29} } Ukraine CyberWar Overview
CyclopsBlink Cobalt Strike GraphSteel GrimPlant HermeticWiper HermeticWizard MicroBackdoor PartyTicket Saint Bot Scieron WhisperGate
2022-03-25GOV.UAState Service of Special Communication and Information Protection of Ukraine (CIP)
@online{cip:20220325:who:e75f0ac, author = {State Service of Special Communication and Information Protection of Ukraine (CIP)}, title = {{Who is behind the Cyberattacks on Ukraine's Critical Information Infrastructure: Statistics for March 15-22}}, date = {2022-03-25}, organization = {GOV.UA}, url = {https://cip.gov.ua/en/news/khto-stoyit-za-kiberatakami-na-ukrayinsku-kritichnu-informaciinu-infrastrukturu-statistika-15-22-bereznya}, language = {English}, urldate = {2022-08-05} } Who is behind the Cyberattacks on Ukraine's Critical Information Infrastructure: Statistics for March 15-22
Xloader Agent Tesla CaddyWiper Cobalt Strike DoubleZero GraphSteel GrimPlant HeaderTip HermeticWiper IsaacWiper MicroBackdoor Pandora RAT
2022-03-14QianxinRed Raindrop Team
@online{team:20220314:analysis:9a058f9, author = {Red Raindrop Team}, title = {{Analysis Of Attack Activities Of Suspected APT Organization UNC1151 Against Ukraine And Other Countries}}, date = {2022-03-14}, organization = {Qianxin}, url = {https://ti.qianxin.com/blog/articles/Analysis-of-attack-activities-of-suspected-aptorganization-unc1151-against-ukraine-and-other-countries/}, language = {Chinese}, urldate = {2022-03-15} } Analysis Of Attack Activities Of Suspected APT Organization UNC1151 Against Ukraine And Other Countries
MicroBackdoor
2022-03-08Cluster25Cluster25
@online{cluster25:20220308:ghostwriter:3f0d3c1, author = {Cluster25}, title = {{GhostWriter / UNC1151 adopts MicroBackdoor Variants in Cyber Operations against Ukraine}}, date = {2022-03-08}, organization = {Cluster25}, url = {https://cluster25.io/2022/03/08/ghostwriter-unc1151-adopts-microbackdoor-variants-in-cyber-operations-against-targets-in-ukraine/}, language = {English}, urldate = {2022-03-10} } GhostWriter / UNC1151 adopts MicroBackdoor Variants in Cyber Operations against Ukraine
MicroBackdoor
2022-03-07Cert-UACert-UA
@online{certua:20220307:uac0051:18afbc7, author = {Cert-UA}, title = {{UAC-0051 (UNC1151) Cyberattack on Ukrainian State Organizations Using MicroBackdoor Malware (CERT-UA#4109)}}, date = {2022-03-07}, organization = {Cert-UA}, url = {https://cert.gov.ua/article/37626}, language = {Ukrainian}, urldate = {2022-03-08} } UAC-0051 (UNC1151) Cyberattack on Ukrainian State Organizations Using MicroBackdoor Malware (CERT-UA#4109)
MicroBackdoor
2021-05-04Cr4sh
@online{cr4sh:20210504:cr4sh:3c1597c, author = {Cr4sh}, title = {{Cr4sh / MicroBackdoor : Small and convenient C2 tool for Windows targets}}, date = {2021-05-04}, url = {https://github.com/cr4sh/microbackdoor}, language = {English}, urldate = {2021-05-04} } Cr4sh / MicroBackdoor : Small and convenient C2 tool for Windows targets
MicroBackdoor
Yara Rules
[TLP:WHITE] win_microbackdoor_auto (20221125 | Detects win.microbackdoor.)
rule win_microbackdoor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-11-21"
        version = "1"
        description = "Detects win.microbackdoor."
        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.microbackdoor"
        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 = { 7503 56 ffd7 e8???????? }
            // n = 4, score = 100
            //   7503                 | mov                 edx, eax
            //   56                   | dec                 esp
            //   ffd7                 | lea                 eax, [ebp - 0x78]
            //   e8????????           |                     

        $sequence_1 = { 4889b42480020000 4889bc2488020000 4c89a42450020000 4c89ac2448020000 }
            // n = 4, score = 100
            //   4889b42480020000     | dec                 eax
            //   4889bc2488020000     | mov                 dword ptr [esp + 0x360], ebx
            //   4c89a42450020000     | dec                 eax
            //   4c89ac2448020000     | mov                 ebx, edx

        $sequence_2 = { 85c0 743a 8dbdd0fdffff ff750c ff7508 57 }
            // n = 6, score = 100
            //   85c0                 | cmp                 eax, -1
            //   743a                 | je                  0x53
            //   8dbdd0fdffff         | movzx               ecx, di
            //   ff750c               | mov                 dword ptr [esp + 0x24], esi
            //   ff7508               | dec                 ecx
            //   57                   | mov                 ecx, esi

        $sequence_3 = { ff15???????? 8b4334 83e800 7440 83e801 742a 83e801 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   8b4334               | dec                 eax
            //   83e800               | lea                 edx, [esp + 0x70]
            //   7440                 | dec                 eax
            //   83e801               | lea                 ecx, [esp + 0x50]
            //   742a                 | setne               bl
            //   83e801               | mov                 dword ptr [esp + 0x38], edi

        $sequence_4 = { 4c8bf9 488d0de0670000 48899c2460030000 488bda 33f6 e8???????? }
            // n = 6, score = 100
            //   4c8bf9               | dec                 eax
            //   488d0de0670000       | mov                 dword ptr [ebp], eax
            //   48899c2460030000     | dec                 eax
            //   488bda               | mov                 eax, dword ptr [esp + 0x78]
            //   33f6                 | mov                 ecx, esi
            //   e8????????           |                     

        $sequence_5 = { ff15???????? 46 83c738 3bb5ccfdffff }
            // n = 4, score = 100
            //   ff15????????         |                     
            //   46                   | mov                 eax, esp
            //   83c738               | dec                 eax
            //   3bb5ccfdffff         | lea                 ecx, [0x677c]

        $sequence_6 = { 488d0d7c670000 8bd0 e8???????? e9???????? 4c8d4588 488d542470 488d4c2450 }
            // n = 7, score = 100
            //   488d0d7c670000       | mov                 dword ptr [esp + 0x288], edi
            //   8bd0                 | dec                 esp
            //   e8????????           |                     
            //   e9????????           |                     
            //   4c8d4588             | mov                 dword ptr [esp + 0x250], esp
            //   488d542470           | dec                 esp
            //   488d4c2450           | mov                 dword ptr [esp + 0x248], ebp

        $sequence_7 = { 8d450c 33f6 50 8d45f8 }
            // n = 4, score = 100
            //   8d450c               | lea                 edi, [ebp - 0x230]
            //   33f6                 | push                dword ptr [ebp + 0xc]
            //   50                   | push                dword ptr [ebp + 8]
            //   8d45f8               | push                edi

        $sequence_8 = { 498bce ff15???????? 4863ce 488d542450 4d8bc4 }
            // n = 5, score = 100
            //   498bce               | jne                 0xff
            //   ff15????????         |                     
            //   4863ce               | dec                 eax
            //   488d542450           | mov                 dword ptr [esp + 0x280], esi
            //   4d8bc4               | dec                 eax

        $sequence_9 = { 833d????????05 488945f8 48894500 488b442478 8bce }
            // n = 5, score = 100
            //   833d????????05       |                     
            //   488945f8             | dec                 eax
            //   48894500             | lea                 ecx, [0x6c59]
            //   488b442478           | dec                 eax
            //   8bce                 | mov                 dword ptr [ebp - 8], eax

        $sequence_10 = { ff7508 ff15???????? eb06 ff15???????? 53 ff75fc ff15???????? }
            // n = 7, score = 100
            //   ff7508               | dec                 eax
            //   ff15????????         |                     
            //   eb06                 | lea                 ecx, [esp + 0x60]
            //   ff15????????         |                     
            //   53                   | test                eax, eax
            //   ff75fc               | je                  0x3e
            //   ff15????????         |                     

        $sequence_11 = { ff15???????? 488bd8 4883f8ff 7451 0fb7cf 89742424 }
            // n = 6, score = 100
            //   ff15????????         |                     
            //   488bd8               | xor                 esi, esi
            //   4883f8ff             | movzx               eax, byte ptr [edx + ecx]
            //   7451                 | dec                 eax
            //   0fb7cf               | inc                 ecx
            //   89742424             | cmp                 al, byte ptr [ebx + ecx - 1]

        $sequence_12 = { 751c 8b3d???????? ffd7 ff15???????? }
            // n = 4, score = 100
            //   751c                 | sub                 esp, 0xa4
            //   8b3d????????         |                     
            //   ffd7                 | push                esi
            //   ff15????????         |                     

        $sequence_13 = { 81eca4000000 56 57 bf9c000000 8d855cffffff }
            // n = 5, score = 100
            //   81eca4000000         | dec                 eax
            //   56                   | arpl                si, cx
            //   57                   | dec                 eax
            //   bf9c000000           | lea                 edx, [esp + 0x50]
            //   8d855cffffff         | dec                 ebp

        $sequence_14 = { e9???????? 448b4310 8b530c 488d0d596c0000 }
            // n = 4, score = 100
            //   e9????????           |                     
            //   448b4310             | inc                 esp
            //   8b530c               | mov                 eax, dword ptr [ebx + 0x10]
            //   488d0d596c0000       | mov                 edx, dword ptr [ebx + 0xc]

        $sequence_15 = { 0fb6040a 48ffc1 3a440bff 0f85f2000000 }
            // n = 4, score = 100
            //   0fb6040a             | dec                 esp
            //   48ffc1               | mov                 edi, ecx
            //   3a440bff             | dec                 eax
            //   0f85f2000000         | lea                 ecx, [0x67e0]

    condition:
        7 of them and filesize < 123904
}
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