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 (20220808 | Detects win.microbackdoor.)
rule win_microbackdoor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        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 = "20220805"
        malpedia_hash = "6ec06c64bcfdbeda64eff021c766b4ce34542b71"
        malpedia_version = "20220808"
        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 = { ba10000000 e8???????? 85c0 0f8456010000 488b0d???????? e8???????? }
            // n = 6, score = 100
            //   ba10000000           | mov                 word ptr [esp + 0xb0], di
            //   e8????????           |                     
            //   85c0                 | inc                 ecx
            //   0f8456010000         | mov                 eax, 4
            //   488b0d????????       |                     
            //   e8????????           |                     

        $sequence_1 = { 68e9fd0000 ff15???????? 8b5d0c 0fb74473fe }
            // n = 4, score = 100
            //   68e9fd0000           | push                0xfde9
            //   ff15????????         |                     
            //   8b5d0c               | mov                 ebx, dword ptr [ebp + 0xc]
            //   0fb74473fe           | movzx               eax, word ptr [ebx + esi*2 - 2]

        $sequence_2 = { eb06 ff15???????? 83c8ff 5f }
            // n = 4, score = 100
            //   eb06                 | jmp                 8
            //   ff15????????         |                     
            //   83c8ff               | or                  eax, 0xffffffff
            //   5f                   | pop                 edi

        $sequence_3 = { 68???????? ffd6 85c0 0f8418010000 }
            // n = 4, score = 100
            //   68????????           |                     
            //   ffd6                 | call                esi
            //   85c0                 | test                eax, eax
            //   0f8418010000         | je                  0x11e

        $sequence_4 = { 8803 42880c12 0fb603 0fb6c9 03c8 81e1ff000080 7d0a }
            // n = 7, score = 100
            //   8803                 | mov                 edx, 0x10
            //   42880c12             | test                eax, eax
            //   0fb603               | je                  0x15c
            //   0fb6c9               | jne                 0x184
            //   03c8                 | cmp                 dword ptr [esp + 0x34], 5
            //   81e1ff000080         | jbe                 0x184
            //   7d0a                 | dec                 eax

        $sequence_5 = { 0f8578010000 837c243405 0f866d010000 4889bc24e8000000 }
            // n = 4, score = 100
            //   0f8578010000         | test                eax, eax
            //   837c243405           | je                  0x20
            //   0f866d010000         | dec                 ecx
            //   4889bc24e8000000     | lea                 ecx, [esi - 2]

        $sequence_6 = { 48897c2430 488bd3 33c9 897c2428 c78424ac00000001000000 6689bc24b0000000 }
            // n = 6, score = 100
            //   48897c2430           | dec                 eax
            //   488bd3               | mov                 ecx, dword ptr [ebp + 0x5e0]
            //   33c9                 | mov                 eax, 1
            //   897c2428             | dec                 eax
            //   c78424ac00000001000000     | mov    dword ptr [esp + 0x30], edi
            //   6689bc24b0000000     | dec                 eax

        $sequence_7 = { 41b804000000 e8???????? 85c0 741e 498d4efe }
            // n = 5, score = 100
            //   41b804000000         | mov                 edx, ebx
            //   e8????????           |                     
            //   85c0                 | xor                 ecx, ecx
            //   741e                 | mov                 dword ptr [esp + 0x28], edi
            //   498d4efe             | mov                 dword ptr [esp + 0xac], 1

        $sequence_8 = { 83cfff 894dfc 85db 757e 8db5a8fcffff 8bc6 50 }
            // n = 7, score = 100
            //   83cfff               | or                  edi, 0xffffffff
            //   894dfc               | mov                 dword ptr [ebp - 4], ecx
            //   85db                 | test                ebx, ebx
            //   757e                 | jne                 0x80
            //   8db5a8fcffff         | lea                 esi, [ebp - 0x358]
            //   8bc6                 | mov                 eax, esi
            //   50                   | push                eax

        $sequence_9 = { 6a01 6a3a ff75fc e8???????? 83c410 }
            // n = 5, score = 100
            //   6a01                 | push                1
            //   6a3a                 | push                0x3a
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10

        $sequence_10 = { ff15???????? 488d0db35d0000 89842490000000 488b942490000000 e8???????? }
            // n = 5, score = 100
            //   ff15????????         |                     
            //   488d0db35d0000       | mov                 dword ptr [esp + 0xe8], edi
            //   89842490000000       | mov                 byte ptr [ebx], al
            //   488b942490000000     | inc                 edx
            //   e8????????           |                     

        $sequence_11 = { 56 50 e8???????? 83c40c 89bd5cffffff }
            // n = 5, score = 100
            //   56                   | push                esi
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   89bd5cffffff         | mov                 dword ptr [ebp - 0xa4], edi

        $sequence_12 = { 6690 8bca 488d7f01 2bcb ffc3 ffc9 }
            // n = 6, score = 100
            //   6690                 | nop                 
            //   8bca                 | mov                 ecx, edx
            //   488d7f01             | dec                 eax
            //   2bcb                 | lea                 edi, [edi + 1]
            //   ffc3                 | sub                 ecx, ebx
            //   ffc9                 | inc                 ebx

        $sequence_13 = { 8d7704 6a2f ff7510 03f0 56 ff15???????? 668b5d14 }
            // n = 7, score = 100
            //   8d7704               | lea                 esi, [edi + 4]
            //   6a2f                 | push                0x2f
            //   ff7510               | push                dword ptr [ebp + 0x10]
            //   03f0                 | add                 esi, eax
            //   56                   | push                esi
            //   ff15????????         |                     
            //   668b5d14             | mov                 bx, word ptr [ebp + 0x14]

        $sequence_14 = { ff15???????? 3bc7 74aa 85c0 0f44c7 ebab }
            // n = 6, score = 100
            //   ff15????????         |                     
            //   3bc7                 | cmp                 eax, edi
            //   74aa                 | je                  0xffffffac
            //   85c0                 | test                eax, eax
            //   0f44c7               | cmove               eax, edi
            //   ebab                 | jmp                 0xffffffad

        $sequence_15 = { 488907 b801000000 eb39 488b8de0050000 ff15???????? b801000000 }
            // n = 6, score = 100
            //   488907               | dec                 ecx
            //   b801000000           | dec                 eax
            //   eb39                 | mov                 dword ptr [edi], eax
            //   488b8de0050000       | mov                 eax, 1
            //   ff15????????         |                     
            //   b801000000           | jmp                 0x40

    condition:
        7 of them and filesize < 123904
}
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