SYMBOLCOMMON_NAMEaka. SYNONYMS
win.sombrat (Back to overview)

SombRAT

Actor(s): [Unnamed group]


There is no description at this point.

References
2021-05-13BlackberryBlackBerry Threat Research and Intelligence Team
@online{team:20210513:threat:15f6212, author = {BlackBerry Threat Research and Intelligence Team}, title = {{Threat Thursday: SombRAT — Always Leave Yourself a Backdoor}}, date = {2021-05-13}, organization = {Blackberry}, url = {https://blogs.blackberry.com/en/2021/05/threat-thursday-sombrat-always-leave-yourself-a-backdoor}, language = {English}, urldate = {2021-05-19} } Threat Thursday: SombRAT — Always Leave Yourself a Backdoor
SombRAT
2020-11-12BlackberryBlackBerry Research and Intelligence team
@online{team:20201112:costaricto:1d1b0c8, author = {BlackBerry Research and Intelligence team}, title = {{The CostaRicto Campaign: Cyber-Espionage Outsourced}}, date = {2020-11-12}, organization = {Blackberry}, url = {https://blogs.blackberry.com/en/2020/11/the-costaricto-campaign-cyber-espionage-outsourced}, language = {English}, urldate = {2020-11-19} } The CostaRicto Campaign: Cyber-Espionage Outsourced
SombRAT
Yara Rules
[TLP:WHITE] win_sombrat_auto (20230125 | Detects win.sombrat.)
rule win_sombrat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.sombrat."
        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.sombrat"
        malpedia_rule_date = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { 85c0 0f85da000000 448bc7 488d4dc8 498bd4 e8???????? 8bd8 }
            // n = 7, score = 200
            //   85c0                 | dec                 eax
            //   0f85da000000         | test                ecx, ecx
            //   448bc7               | je                  0x78c
            //   488d4dc8             | dec                 eax
            //   498bd4               | cmp                 dword ptr [ecx], 0
            //   e8????????           |                     
            //   8bd8                 | je                  0x78c

        $sequence_1 = { 74ed 488bd0 498b03 4d8b4b10 80781900 7519 4180791900 }
            // n = 7, score = 200
            //   74ed                 | dec                 eax
            //   488bd0               | mov                 dword ptr [esi + 0x18], 0xf
            //   498b03               | dec                 ecx
            //   4d8b4b10             | mov                 eax, esi
            //   80781900             | mov                 byte ptr [esi], 0
            //   7519                 | ja                  0x16bd
            //   4180791900           | cmp                 dword ptr [ecx + 0xc], 0x17

        $sequence_2 = { 488d1401 e8???????? 488b83e0000000 41b9bb120000 4889442430 4d8bc6 }
            // n = 6, score = 200
            //   488d1401             | dec                 eax
            //   e8????????           |                     
            //   488b83e0000000       | add                 ecx, esi
            //   41b9bb120000         | dec                 ecx
            //   4889442430           | mov                 edx, esi
            //   4d8bc6               | dec                 eax

        $sequence_3 = { b8809fffff ebde 488b01 4533c0 4885c0 7476 83780402 }
            // n = 7, score = 200
            //   b8809fffff           | mov                 ecx, 0x8f4
            //   ebde                 | dec                 esp
            //   488b01               | cmp                 dword ptr [edi + 0xe0], edx
            //   4533c0               | jne                 0xb27
            //   4885c0               | cmp                 dword ptr [edi + 0x18], 3
            //   7476                 | inc                 ecx
            //   83780402             | mov                 ecx, 0x14d1

        $sequence_4 = { 7510 8b420c 39410c 7508 8b4210 394110 7f28 }
            // n = 7, score = 200
            //   7510                 | dec                 ecx
            //   8b420c               | mov                 ebp, dword ptr [ebx + 0x38]
            //   39410c               | setne               dl
            //   7508                 | inc                 ecx
            //   8b4210               | call                dword ptr [eax + 0x20]
            //   394110               | dec                 ebp
            //   7f28                 | mov                 dword ptr [edi + 0x38], ebp

        $sequence_5 = { 740c 4585ff 7507 85c0 7403 448bf3 85d2 }
            // n = 7, score = 200
            //   740c                 | test                esi, esi
            //   4585ff               | je                  0x1175
            //   7507                 | dec                 eax
            //   85c0                 | test                edi, edi
            //   7403                 | je                  0x1175
            //   448bf3               | dec                 esp
            //   85d2                 | mov                 eax, edi

        $sequence_6 = { 4183e901 7421 4183e901 7416 4183e901 740b 4183f901 }
            // n = 7, score = 200
            //   4183e901             | dec                 eax
            //   7421                 | mov                 dword ptr [ecx], eax
            //   4183e901             | dec                 eax
            //   7416                 | lea                 ebx, [edi + 0x18]
            //   4183e901             | dec                 eax
            //   740b                 | lea                 eax, [0x74fc3]
            //   4183f901             | dec                 eax

        $sequence_7 = { e9???????? 8acb 4584f6 741b 0fb6c1 ba0f000000 482bd0 }
            // n = 7, score = 200
            //   e9????????           |                     
            //   8acb                 | inc                 ebp
            //   4584f6               | mov                 byte ptr [ecx - 1], al
            //   741b                 | dec                 ecx
            //   0fb6c1               | mov                 ecx, eax
            //   ba0f000000           | dec                 eax
            //   482bd0               | shr                 ecx, 8

        $sequence_8 = { 80bfe028000000 7512 488b0b 4885c9 740a 488b01 ba01000000 }
            // n = 7, score = 200
            //   80bfe028000000       | mov                 eax, ebx
            //   7512                 | dec                 eax
            //   488b0b               | mov                 ecx, dword ptr [esp + 0x90]
            //   4885c9               | dec                 eax
            //   740a                 | xor                 ecx, esp
            //   488b01               | xor                 edx, edx
            //   ba01000000           | inc                 esp

        $sequence_9 = { bf01000000 448bc7 488b5508 488bcd e8???????? 488bf0 4885c0 }
            // n = 7, score = 200
            //   bf01000000           | dec                 ecx
            //   448bc7               | mov                 dword ptr [eax + 0x10], eax
            //   488b5508             | dec                 eax
            //   488bcd               | mov                 eax, dword ptr [ecx]
            //   e8????????           |                     
            //   488bf0               | cmp                 byte ptr [eax + 0x19], 0
            //   4885c0               | jne                 0xb01

    condition:
        7 of them and filesize < 1466368
}
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