rule win_tclient_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.tclient."
        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.tclient"
        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 = { f7d0 03d7 0bc2 8955f4 33c7 03461c 8db1827e53f7 }
            // n = 7, score = 100
            //   f7d0                 | not                 eax
            //   03d7                 | add                 edx, edi
            //   0bc2                 | or                  eax, edx
            //   8955f4               | mov                 dword ptr [ebp - 0xc], edx
            //   33c7                 | xor                 eax, edi
            //   03461c               | add                 eax, dword ptr [esi + 0x1c]
            //   8db1827e53f7         | lea                 esi, [ecx - 0x8ac817e]

        $sequence_1 = { eb83 83a68c00000000 8bce e8???????? 8bc7 eb05 b853ffffff }
            // n = 7, score = 100
            //   eb83                 | jmp                 0xffffff85
            //   83a68c00000000       | and                 dword ptr [esi + 0x8c], 0
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   8bc7                 | mov                 eax, edi
            //   eb05                 | jmp                 7
            //   b853ffffff           | mov                 eax, 0xffffff53

        $sequence_2 = { c1c105 33c7 034b34 8b5da8 03c8 03ce c1c31e }
            // n = 7, score = 100
            //   c1c105               | rol                 ecx, 5
            //   33c7                 | xor                 eax, edi
            //   034b34               | add                 ecx, dword ptr [ebx + 0x34]
            //   8b5da8               | mov                 ebx, dword ptr [ebp - 0x58]
            //   03c8                 | add                 ecx, eax
            //   03ce                 | add                 ecx, esi
            //   c1c31e               | rol                 ebx, 0x1e

        $sequence_3 = { 0fb7c2 42 c6440804c0 0fb7c2 42 c644080414 0fb7c2 }
            // n = 7, score = 100
            //   0fb7c2               | movzx               eax, dx
            //   42                   | inc                 edx
            //   c6440804c0           | mov                 byte ptr [eax + ecx + 4], 0xc0
            //   0fb7c2               | movzx               eax, dx
            //   42                   | inc                 edx
            //   c644080414           | mov                 byte ptr [eax + ecx + 4], 0x14
            //   0fb7c2               | movzx               eax, dx

        $sequence_4 = { bbff00ff00 c1c008 c1ce08 23c3 81e600ff00ff 0bf0 8b4204 }
            // n = 7, score = 100
            //   bbff00ff00           | mov                 ebx, 0xff00ff
            //   c1c008               | rol                 eax, 8
            //   c1ce08               | ror                 esi, 8
            //   23c3                 | and                 eax, ebx
            //   81e600ff00ff         | and                 esi, 0xff00ff00
            //   0bf0                 | or                  esi, eax
            //   8b4204               | mov                 eax, dword ptr [edx + 4]

        $sequence_5 = { e8???????? 83c40c 85db 7e38 8b953cffffff 8bce 6a0d }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   85db                 | test                ebx, ebx
            //   7e38                 | jle                 0x3a
            //   8b953cffffff         | mov                 edx, dword ptr [ebp - 0xc4]
            //   8bce                 | mov                 ecx, esi
            //   6a0d                 | push                0xd

        $sequence_6 = { 6800080000 53 8d85f4f4ffff 50 e8???????? 83c430 8d85fcfdffff }
            // n = 7, score = 100
            //   6800080000           | push                0x800
            //   53                   | push                ebx
            //   8d85f4f4ffff         | lea                 eax, [ebp - 0xb0c]
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c430               | add                 esp, 0x30
            //   8d85fcfdffff         | lea                 eax, [ebp - 0x204]

        $sequence_7 = { 5d c3 55 8bec 85c9 7429 85d2 }
            // n = 7, score = 100
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   85c9                 | test                ecx, ecx
            //   7429                 | je                  0x2b
            //   85d2                 | test                edx, edx

        $sequence_8 = { 8be5 5d c3 55 8bec 85c9 7435 }
            // n = 7, score = 100
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   85c9                 | test                ecx, ecx
            //   7435                 | je                  0x37

        $sequence_9 = { 7405 e8???????? b81c010000 8d8efc010000 8819 41 83e801 }
            // n = 7, score = 100
            //   7405                 | je                  7
            //   e8????????           |                     
            //   b81c010000           | mov                 eax, 0x11c
            //   8d8efc010000         | lea                 ecx, [esi + 0x1fc]
            //   8819                 | mov                 byte ptr [ecx], bl
            //   41                   | inc                 ecx
            //   83e801               | sub                 eax, 1

    condition:
        7 of them and filesize < 1063936
}