rule win_spedear_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.spedear."
        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.spedear"
        malpedia_rule_date = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        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 = { 83e207 03c2 c1f803 83c40c 85c0 }
            // n = 5, score = 600
            //   83e207               | and                 edx, 7
            //   03c2                 | add                 eax, edx
            //   c1f803               | sar                 eax, 3
            //   83c40c               | add                 esp, 0xc
            //   85c0                 | test                eax, eax

        $sequence_1 = { 50 e8???????? 8b7e0c 895e10 }
            // n = 4, score = 500
            //   50                   | push                eax
            //   e8????????           |                     
            //   8b7e0c               | mov                 edi, dword ptr [esi + 0xc]
            //   895e10               | mov                 dword ptr [esi + 0x10], ebx

        $sequence_2 = { 8a5f06 50 894608 e8???????? }
            // n = 4, score = 500
            //   8a5f06               | mov                 bl, byte ptr [edi + 6]
            //   50                   | push                eax
            //   894608               | mov                 dword ptr [esi + 8], eax
            //   e8????????           |                     

        $sequence_3 = { 57 8bf0 8bfa 8bc7 2507000080 7905 48 }
            // n = 7, score = 400
            //   57                   | sar                 eax, 3
            //   8bf0                 | add                 esp, 0xc
            //   8bfa                 | test                eax, eax
            //   8bc7                 | add                 eax, edx
            //   2507000080           | sar                 eax, 3
            //   7905                 | add                 esp, 0xc
            //   48                   | test                eax, eax

        $sequence_4 = { 33ce 836c241001 8bf3 75ad 8b4244 8b74241c 8b5240 }
            // n = 7, score = 400
            //   33ce                 | xor                 ecx, esi
            //   836c241001           | sub                 dword ptr [esp + 0x10], 1
            //   8bf3                 | mov                 esi, ebx
            //   75ad                 | jne                 0xffffffaf
            //   8b4244               | mov                 eax, dword ptr [edx + 0x44]
            //   8b74241c             | mov                 esi, dword ptr [esp + 0x1c]
            //   8b5240               | mov                 edx, dword ptr [edx + 0x40]

        $sequence_5 = { 50 8bde e8???????? 5b }
            // n = 4, score = 400
            //   50                   | push                eax
            //   8bde                 | mov                 ebx, esi
            //   e8????????           |                     
            //   5b                   | pop                 ebx

        $sequence_6 = { 8d5304 8d4f06 52 e8???????? 8b4718 }
            // n = 5, score = 400
            //   8d5304               | and                 edx, 7
            //   8d4f06               | add                 eax, edx
            //   52                   | sar                 eax, 3
            //   e8????????           |                     
            //   8b4718               | add                 esp, 0xc

        $sequence_7 = { 6a00 68???????? e8???????? 83c40c 68d0070000 }
            // n = 5, score = 400
            //   6a00                 | push                0
            //   68????????           |                     
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   68d0070000           | push                0x7d0

        $sequence_8 = { 50 e8???????? 83c420 33c0 396f1c }
            // n = 5, score = 400
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c420               | add                 esp, 0x20
            //   33c0                 | xor                 eax, eax
            //   396f1c               | cmp                 dword ptr [edi + 0x1c], ebp

        $sequence_9 = { 894618 ffd7 89461c 5f }
            // n = 4, score = 400
            //   894618               | mov                 dword ptr [esi + 0x18], eax
            //   ffd7                 | call                edi
            //   89461c               | mov                 dword ptr [esi + 0x1c], eax
            //   5f                   | pop                 edi

        $sequence_10 = { 8bc7 5e 5f 5b 5d c3 6a08 }
            // n = 7, score = 300
            //   8bc7                 | mov                 eax, edi
            //   5e                   | pop                 esi
            //   5f                   | pop                 edi
            //   5b                   | pop                 ebx
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   6a08                 | push                8

        $sequence_11 = { 833e00 741a 6a00 6a00 ff7608 ff5604 }
            // n = 6, score = 300
            //   833e00               | cmp                 dword ptr [esi], 0
            //   741a                 | je                  0x1c
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   ff7608               | push                dword ptr [esi + 8]
            //   ff5604               | call                dword ptr [esi + 4]

        $sequence_12 = { 6a00 ff7608 ff5604 6800800000 6a00 ff7608 }
            // n = 6, score = 300
            //   6a00                 | push                0
            //   ff7608               | push                dword ptr [esi + 8]
            //   ff5604               | call                dword ptr [esi + 4]
            //   6800800000           | push                0x8000
            //   6a00                 | push                0
            //   ff7608               | push                dword ptr [esi + 8]

        $sequence_13 = { 394878 7456 39487c 7451 }
            // n = 4, score = 300
            //   394878               | cmp                 dword ptr [eax + 0x78], ecx
            //   7456                 | je                  0x58
            //   39487c               | cmp                 dword ptr [eax + 0x7c], ecx
            //   7451                 | je                  0x53

        $sequence_14 = { c3 6820040000 b8???????? e8???????? 8b7d08 33db be03010000 }
            // n = 7, score = 200
            //   c3                   | ret                 
            //   6820040000           | push                0x420
            //   b8????????           |                     
            //   e8????????           |                     
            //   8b7d08               | mov                 edi, dword ptr [ebp + 8]
            //   33db                 | xor                 ebx, ebx
            //   be03010000           | mov                 esi, 0x103

        $sequence_15 = { 418b0c86 413bcc 7608 428d0422 3bc8 72a8 488bc1 }
            // n = 7, score = 100
            //   418b0c86             | sub                 esp, ebx
            //   413bcc               | nop                 dword ptr [eax]
            //   7608                 | inc                 esp
            //   428d0422             | mov                 eax, edx
            //   3bc8                 | dec                 ebp
            //   72a8                 | mov                 ecx, esi
            //   488bc1               | nop                 word ptr [eax + eax]

        $sequence_16 = { 41be04000000 4d2be3 0f1f00 448bc2 4d8bce 66660f1f840000000000 0fb60431 }
            // n = 7, score = 100
            //   41be04000000         | dec                 eax
            //   4d2be3               | lea                 edx, [esp + 0x30]
            //   0f1f00               | dec                 eax
            //   448bc2               | lea                 eax, [esp + 0x40]
            //   4d8bce               | inc                 ecx
            //   66660f1f840000000000     | mov    esi, 4
            //   0fb60431             | dec                 ebp

        $sequence_17 = { 6a02 68e8000000 ff15???????? 50 }
            // n = 4, score = 100
            //   6a02                 | push                dword ptr [esi + 8]
            //   68e8000000           | call                dword ptr [esi + 4]
            //   ff15????????         |                     
            //   50                   | push                0x8000

        $sequence_18 = { 8bd9 7418 488d0d2bf00000 e8???????? 85c0 7408 }
            // n = 6, score = 100
            //   8bd9                 | mov                 eax, ecx
            //   7418                 | inc                 esp
            //   488d0d2bf00000       | mov                 esp, dword ptr [eax + 0x88]
            //   e8????????           |                     
            //   85c0                 | dec                 eax
            //   7408                 | mov                 eax, dword ptr [ecx + 0x10]

        $sequence_19 = { ff2485916d2300 838de8fdffffff 89b588fdffff 89b5bcfdffff 89b5c8fdffff 89b5ccfdffff }
            // n = 6, score = 100
            //   ff2485916d2300       | push                0
            //   838de8fdffffff       | push                0
            //   89b588fdffff         | push                dword ptr [esi + 8]
            //   89b5bcfdffff         | call                dword ptr [esi + 4]
            //   89b5c8fdffff         | push                dword ptr [esi + 8]
            //   89b5ccfdffff         | call                dword ptr [esi + 4]

        $sequence_20 = { e8???????? 448b5e18 44895f10 8b4e1c e8???????? }
            // n = 5, score = 100
            //   e8????????           |                     
            //   448b5e18             | dec                 esp
            //   44895f10             | mov                 dword ptr [esp + 0x10], ebp
            //   8b4e1c               | dec                 esp
            //   e8????????           |                     

        $sequence_21 = { e8???????? 4c8d1d738c0000 4c891b 488bc3 4883c420 }
            // n = 5, score = 100
            //   e8????????           |                     
            //   4c8d1d738c0000       | mov                 dword ptr [esp + 8], esi
            //   4c891b               | inc                 esi
            //   488bc3               | mov                 esi, dword ptr [eax + 0x1c]
            //   4883c420             | inc                 esi

        $sequence_22 = { 33ff 8bf3 e8???????? 83bdd0f7ffff10 }
            // n = 4, score = 100
            //   33ff                 | push                0
            //   8bf3                 | push                dword ptr [esi + 8]
            //   e8????????           |                     
            //   83bdd0f7ffff10       | je                  0x1c

        $sequence_23 = { 448ba088000000 488b4110 4c896c2410 4c89742408 468b74201c 468b6c2024 }
            // n = 6, score = 100
            //   448ba088000000       | movzx               eax, byte ptr [ecx + esi]
            //   488b4110             | inc                 ecx
            //   4c896c2410           | mov                 ecx, dword ptr [esi + eax*4]
            //   4c89742408           | inc                 ecx
            //   468b74201c           | cmp                 ecx, esp
            //   468b6c2024           | jbe                 0xd

        $sequence_24 = { 41b804010000 c744243004010000 e8???????? 488b4c2438 488d542430 488d442440 }
            // n = 6, score = 100
            //   41b804010000         | inc                 ecx
            //   c744243004010000     | mov                 eax, 0x104
            //   e8????????           |                     
            //   488b4c2438           | mov                 dword ptr [esp + 0x30], 0x104
            //   488d542430           | dec                 eax
            //   488d442440           | mov                 ecx, dword ptr [esp + 0x38]

        $sequence_25 = { 488bfa 488bd9 488d058d760000 488981a0000000 c7411c01000000 }
            // n = 5, score = 100
            //   488bfa               | inc                 edx
            //   488bd9               | lea                 eax, [edx]
            //   488d058d760000       | cmp                 ecx, eax
            //   488981a0000000       | jb                  0xffffffb5
            //   c7411c01000000       | dec                 eax

        $sequence_26 = { 890d???????? 33d2 a3???????? 890d???????? }
            // n = 4, score = 100
            //   890d????????         |                     
            //   33d2                 | push                0x8000
            //   a3????????           |                     
            //   890d????????         |                     

    condition:
        7 of them and filesize < 188416
}