rule win_matryoshka_rat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.matryoshka_rat."
        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.matryoshka_rat"
        malpedia_rule_date = "20220405"
        malpedia_hash = "ecd38294bd47d5589be5cd5490dc8bb4804afc2a"
        malpedia_version = "20220411"
        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 = { b037 c3 b073 c3 }
            // n = 4, score = 400
            //   b037                 | mov                 al, 0x37
            //   c3                   | ret                 
            //   b073                 | mov                 al, 0x73
            //   c3                   | ret                 

        $sequence_1 = { b06f c3 b063 c3 }
            // n = 4, score = 400
            //   b06f                 | mov                 al, 0x6f
            //   c3                   | ret                 
            //   b063                 | mov                 al, 0x63
            //   c3                   | ret                 

        $sequence_2 = { 7406 6683f85c 7503 488bca }
            // n = 4, score = 200
            //   7406                 | call                dword ptr [edx + 0x10]
            //   6683f85c             | dec                 eax
            //   7503                 | lea                 ecx, dword ptr [0x4bb94]
            //   488bca               | dec                 eax

        $sequence_3 = { 8b45f8 8901 8bce e8???????? }
            // n = 4, score = 200
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   8901                 | mov                 dword ptr [ecx], eax
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     

        $sequence_4 = { 8b45f8 83c41c 0118 015e04 }
            // n = 4, score = 200
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   83c41c               | add                 esp, 0x1c
            //   0118                 | add                 dword ptr [eax], ebx
            //   015e04               | add                 dword ptr [esi + 4], ebx

        $sequence_5 = { 7406 488d5808 ebc2 488d15a2110400 }
            // n = 4, score = 200
            //   7406                 | dec                 eax
            //   488d5808             | mov                 edx, dword ptr [ecx]
            //   ebc2                 | call                dword ptr [edx + 0x10]
            //   488d15a2110400       | dec                 eax

        $sequence_6 = { 7406 488b11 ff5210 488d0d94bb0400 }
            // n = 4, score = 200
            //   7406                 | dec                 eax
            //   488b11               | lea                 ecx, dword ptr [0x4c9cb]
            //   ff5210               | je                  8
            //   488d0d94bb0400       | dec                 eax

        $sequence_7 = { 7406 6683f85c 7504 4c8d7902 }
            // n = 4, score = 200
            //   7406                 | jmp                 0xffffffc4
            //   6683f85c             | dec                 eax
            //   7504                 | lea                 edx, dword ptr [0x411a2]
            //   4c8d7902             | dec                 eax

        $sequence_8 = { 8b45f8 89841fcc060000 89b41fc0060000 8b841fa0060000 }
            // n = 4, score = 200
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   89841fcc060000       | mov                 dword ptr [edi + ebx + 0x6cc], eax
            //   89b41fc0060000       | mov                 dword ptr [edi + ebx + 0x6c0], esi
            //   8b841fa0060000       | mov                 eax, dword ptr [edi + ebx + 0x6a0]

        $sequence_9 = { 7406 488b01 ff5010 488b8df0000000 4885c9 7406 }
            // n = 6, score = 200
            //   7406                 | je                  8
            //   488b01               | dec                 eax
            //   ff5010               | mov                 eax, dword ptr [ecx]
            //   488b8df0000000       | call                dword ptr [eax + 0x10]
            //   4885c9               | dec                 eax
            //   7406                 | mov                 ecx, dword ptr [ebp + 0xf0]

        $sequence_10 = { 7406 488b01 ff5010 488d0dcbc90400 e8???????? ff15???????? }
            // n = 6, score = 200
            //   7406                 | dec                 eax
            //   488b01               | mov                 eax, dword ptr [ecx]
            //   ff5010               | call                dword ptr [eax + 0x10]
            //   488d0dcbc90400       | dec                 eax
            //   e8????????           |                     
            //   ff15????????         |                     

        $sequence_11 = { 8b45f8 83c404 eb23 8b8684af0600 33d2 0fb6843070af0100 }
            // n = 6, score = 200
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   83c404               | add                 esp, 4
            //   eb23                 | jmp                 0x25
            //   8b8684af0600         | mov                 eax, dword ptr [esi + 0x6af84]
            //   33d2                 | xor                 edx, edx
            //   0fb6843070af0100     | movzx               eax, byte ptr [eax + esi + 0x1af70]

        $sequence_12 = { 8b45f8 8933 894734 8bd3 }
            // n = 4, score = 200
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   8933                 | mov                 dword ptr [ebx], esi
            //   894734               | mov                 dword ptr [edi + 0x34], eax
            //   8bd3                 | mov                 edx, ebx

        $sequence_13 = { 8b45f8 8945d4 895df4 8b5df8 }
            // n = 4, score = 200
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   8945d4               | mov                 dword ptr [ebp - 0x2c], eax
            //   895df4               | mov                 dword ptr [ebp - 0xc], ebx
            //   8b5df8               | mov                 ebx, dword ptr [ebp - 8]

    condition:
        7 of them and filesize < 843776
}

rule win_matryoshka_rat_w0 {
    meta:
        author = "Florian Roth"
        description = "Detects Matryoshka RAT used in Operation Wilted Tulip"
        reference = "http://www.clearskysec.com/tulip"
        date = "2017-07-23"
        hash = "6f208473df0d31987a4999eeea04d24b069fdb6a8245150aa91dfdc063cd64ab"
        hash = "6cc1f4ecd28b833c978c8e21a20a002459b4a6c21a4fbaad637111aa9d5b1a32"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.matryoshka_rat"
        malpedia_version = "20170914"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $s1 = "%S:\\Users\\public" fullword wide
        $s2 = "ntuser.dat.swp" fullword wide
        $s3 = "Job Save / Load Config" fullword wide
        $s4 = ".?AVPSCL_CLASS_JOB_SAVE_CONFIG@@" fullword ascii
        $s5 = "winupdate64.com" fullword ascii
        $s6 = "Job Save KeyLogger" fullword wide
    condition:
    filesize < 1000KB and 5 of them
}