rule win_chainshot_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.chainshot."
        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.chainshot"
        malpedia_rule_date = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { ffc9 7438 ffc9 742b ffc9 741e }
            // n = 6, score = 300
            //   ffc9                 | mov                 dword ptr [esp + 0x28], esi
            //   7438                 | jmp                 0x49b
            //   ffc9                 | cmp                 dword ptr [ebp + 0xc], edi
            //   742b                 | jne                 0x447
            //   ffc9                 | test                eax, eax
            //   741e                 | je                  0x43b

        $sequence_1 = { 84c0 7507 b901050080 ebbd b901020000 e8???????? e8???????? }
            // n = 7, score = 300
            //   84c0                 | add                 edi, 0xc
            //   7507                 | add                 edi, esi
            //   b901050080           | jmp                 0x11cc
            //   ebbd                 | mov                 esi, dword ptr [edi]
            //   b901020000           | lea                 eax, [ebp - 0x208]
            //   e8????????           |                     
            //   e8????????           |                     

        $sequence_2 = { 7408 ffd1 8905???????? bf7e000080 }
            // n = 4, score = 300
            //   7408                 | test                al, al
            //   ffd1                 | mov                 word ptr [esp + 0x28], ax
            //   8905????????         |                     
            //   bf7e000080           | mov                 eax, 0x100

        $sequence_3 = { b8ffff0000 663bc5 7513 bb17000080 eb33 }
            // n = 5, score = 300
            //   b8ffff0000           | lea                 ecx, [edi + 0x460]
            //   663bc5               | dec                 eax
            //   7513                 | cmp                 dword ptr [ecx], 0
            //   bb17000080           | je                  0xa47
            //   eb33                 | lea                 ecx, [edi + 0x1b88]

        $sequence_4 = { 7408 ffd0 8905???????? b849000080 e9???????? }
            // n = 5, score = 300
            //   7408                 | mov                 ebx, 0x22
            //   ffd0                 | dec                 esp
            //   8905????????         |                     
            //   b849000080           | mov                 word ptr [ecx], bx
            //   e9????????           |                     

        $sequence_5 = { b849890000 668901 c7410348894c24 c6410708 c7410848895424 }
            // n = 5, score = 300
            //   b849890000           | dec                 eax
            //   668901               | test                esi, esi
            //   c7410348894c24       | lea                 eax, [ebx + 0x4a]
            //   c6410708             | mov                 word ptr [ebp + 0x200], ax
            //   c7410848895424       | dec                 esp

        $sequence_6 = { e9???????? 83e827 0f844e0e0000 ffc8 0f84d8110000 }
            // n = 5, score = 300
            //   e9????????           |                     
            //   83e827               | dec                 eax
            //   0f844e0e0000         | lea                 ecx, [0x2557d]
            //   ffc8                 | dec                 eax
            //   0f84d8110000         | lea                 ecx, [0x255ad]

        $sequence_7 = { 33d2 84c0 b900050080 7405 b908020000 }
            // n = 5, score = 300
            //   33d2                 | inc                 ecx
            //   84c0                 | lea                 ecx, [eax - 0x10]
            //   b900050080           | and                 edi, eax
            //   7405                 | ja                  0x6ae
            //   b908020000           | shr                 eax, 1

        $sequence_8 = { 33d2 b902060080 e8???????? 32db }
            // n = 4, score = 300
            //   33d2                 | xor                 eax, esp
            //   b902060080           | mov                 dword ptr [esp + 0x838], eax
            //   e8????????           |                     
            //   32db                 | push                esi

        $sequence_9 = { 7408 ffd0 8905???????? bb65000080 }
            // n = 4, score = 300
            //   7408                 | js                  0x11c1
            //   ffd0                 | mov                 word ptr [ecx], bp
            //   8905????????         |                     
            //   bb65000080           | inc                 ebp

    condition:
        7 of them and filesize < 802816
}