rule win_greenshaitan_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.greenshaitan."
        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.greenshaitan"
        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 = { 57 8bf9 8bda 57 e8???????? 8bf0 85f6 }
            // n = 7, score = 100
            //   57                   | push                edi
            //   8bf9                 | mov                 edi, ecx
            //   8bda                 | mov                 ebx, edx
            //   57                   | push                edi
            //   e8????????           |                     
            //   8bf0                 | mov                 esi, eax
            //   85f6                 | test                esi, esi

        $sequence_1 = { 8b442418 8b4c2424 83ec14 53 8b5c2438 55 56 }
            // n = 7, score = 100
            //   8b442418             | mov                 eax, dword ptr [esp + 0x18]
            //   8b4c2424             | mov                 ecx, dword ptr [esp + 0x24]
            //   83ec14               | sub                 esp, 0x14
            //   53                   | push                ebx
            //   8b5c2438             | mov                 ebx, dword ptr [esp + 0x38]
            //   55                   | push                ebp
            //   56                   | push                esi

        $sequence_2 = { 889c2480020000 e8???????? 8d573c 8d742430 e8???????? 6a00 50 }
            // n = 7, score = 100
            //   889c2480020000       | mov                 byte ptr [esp + 0x280], bl
            //   e8????????           |                     
            //   8d573c               | lea                 edx, [edi + 0x3c]
            //   8d742430             | lea                 esi, [esp + 0x30]
            //   e8????????           |                     
            //   6a00                 | push                0
            //   50                   | push                eax

        $sequence_3 = { ffd0 56 53 e8???????? 5b 8be5 }
            // n = 6, score = 100
            //   ffd0                 | call                eax
            //   56                   | push                esi
            //   53                   | push                ebx
            //   e8????????           |                     
            //   5b                   | pop                 ebx
            //   8be5                 | mov                 esp, ebp

        $sequence_4 = { 8bf0 c1ee02 8a9e685b6e00 0fb6d2 8bf2 83e003 }
            // n = 6, score = 100
            //   8bf0                 | mov                 esi, eax
            //   c1ee02               | shr                 esi, 2
            //   8a9e685b6e00         | mov                 bl, byte ptr [esi + 0x6e5b68]
            //   0fb6d2               | movzx               edx, dl
            //   8bf2                 | mov                 esi, edx
            //   83e003               | and                 eax, 3

        $sequence_5 = { 8d7c2474 895c246c 885c245c e8???????? 50 bf???????? 8d74241c }
            // n = 7, score = 100
            //   8d7c2474             | lea                 edi, [esp + 0x74]
            //   895c246c             | mov                 dword ptr [esp + 0x6c], ebx
            //   885c245c             | mov                 byte ptr [esp + 0x5c], bl
            //   e8????????           |                     
            //   50                   | push                eax
            //   bf????????           |                     
            //   8d74241c             | lea                 esi, [esp + 0x1c]

        $sequence_6 = { 8b0424 7409 83caff 83c408 c20c00 8b542404 }
            // n = 6, score = 100
            //   8b0424               | mov                 eax, dword ptr [esp]
            //   7409                 | je                  0xb
            //   83caff               | or                  edx, 0xffffffff
            //   83c408               | add                 esp, 8
            //   c20c00               | ret                 0xc
            //   8b542404             | mov                 edx, dword ptr [esp + 4]

        $sequence_7 = { 50 8d8f2c010000 51 8d8710010000 50 55 }
            // n = 6, score = 100
            //   50                   | push                eax
            //   8d8f2c010000         | lea                 ecx, [edi + 0x12c]
            //   51                   | push                ecx
            //   8d8710010000         | lea                 eax, [edi + 0x110]
            //   50                   | push                eax
            //   55                   | push                ebp

        $sequence_8 = { 83e703 89442424 85c9 7511 }
            // n = 4, score = 100
            //   83e703               | and                 edi, 3
            //   89442424             | mov                 dword ptr [esp + 0x24], eax
            //   85c9                 | test                ecx, ecx
            //   7511                 | jne                 0x13

        $sequence_9 = { 57 33c0 8d642400 880408 40 3d00010000 7cf5 }
            // n = 7, score = 100
            //   57                   | push                edi
            //   33c0                 | xor                 eax, eax
            //   8d642400             | lea                 esp, [esp]
            //   880408               | mov                 byte ptr [eax + ecx], al
            //   40                   | inc                 eax
            //   3d00010000           | cmp                 eax, 0x100
            //   7cf5                 | jl                  0xfffffff7

    condition:
        7 of them and filesize < 253952
}