rule win_jaku_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.jaku."
        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.jaku"
        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 = { 83c40c 894618 33db 33ff 895df4 eb0b 8b4620 }
            // n = 7, score = 1500
            //   83c40c               | add                 esp, 0xc
            //   894618               | mov                 dword ptr [esi + 0x18], eax
            //   33db                 | xor                 ebx, ebx
            //   33ff                 | xor                 edi, edi
            //   895df4               | mov                 dword ptr [ebp - 0xc], ebx
            //   eb0b                 | jmp                 0xd
            //   8b4620               | mov                 eax, dword ptr [esi + 0x20]

        $sequence_1 = { 7320 897dec 8d7c7da8 0fb707 2bd0 85d2 }
            // n = 6, score = 1500
            //   7320                 | jae                 0x22
            //   897dec               | mov                 dword ptr [ebp - 0x14], edi
            //   8d7c7da8             | lea                 edi, [ebp + edi*2 - 0x58]
            //   0fb707               | movzx               eax, word ptr [edi]
            //   2bd0                 | sub                 edx, eax
            //   85d2                 | test                edx, edx

        $sequence_2 = { 837df800 0f8457040000 8b45fc 8bcf }
            // n = 4, score = 1500
            //   837df800             | cmp                 dword ptr [ebp - 8], 0
            //   0f8457040000         | je                  0x45d
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   8bcf                 | mov                 ecx, edi

        $sequence_3 = { c6451101 8b01 8b5510 8910 830104 8b31 8916 }
            // n = 7, score = 1500
            //   c6451101             | mov                 byte ptr [ebp + 0x11], 1
            //   8b01                 | mov                 eax, dword ptr [ecx]
            //   8b5510               | mov                 edx, dword ptr [ebp + 0x10]
            //   8910                 | mov                 dword ptr [eax], edx
            //   830104               | add                 dword ptr [ecx], 4
            //   8b31                 | mov                 esi, dword ptr [ecx]
            //   8916                 | mov                 dword ptr [esi], edx

        $sequence_4 = { 0f85ff000000 8b5d08 be00400000 53 56 8d85c4bfffff }
            // n = 6, score = 1500
            //   0f85ff000000         | jne                 0x105
            //   8b5d08               | mov                 ebx, dword ptr [ebp + 8]
            //   be00400000           | mov                 esi, 0x4000
            //   53                   | push                ebx
            //   56                   | push                esi
            //   8d85c4bfffff         | lea                 eax, [ebp - 0x403c]

        $sequence_5 = { 6a0f 58 8d4dc6 8b17 }
            // n = 4, score = 1500
            //   6a0f                 | push                0xf
            //   58                   | pop                 eax
            //   8d4dc6               | lea                 ecx, [ebp - 0x3a]
            //   8b17                 | mov                 edx, dword ptr [edi]

        $sequence_6 = { 7423 8d45c8 50 e8???????? 83ff02 }
            // n = 5, score = 1500
            //   7423                 | je                  0x25
            //   8d45c8               | lea                 eax, [ebp - 0x38]
            //   50                   | push                eax
            //   e8????????           |                     
            //   83ff02               | cmp                 edi, 2

        $sequence_7 = { 0f8402120000 39500c 0f84f9110000 3910 7509 }
            // n = 5, score = 1500
            //   0f8402120000         | je                  0x1208
            //   39500c               | cmp                 dword ptr [eax + 0xc], edx
            //   0f84f9110000         | je                  0x11ff
            //   3910                 | cmp                 dword ptr [eax], edx
            //   7509                 | jne                 0xb

        $sequence_8 = { 68???????? ff15???????? c3 b8???????? e8???????? 83ec2c }
            // n = 6, score = 800
            //   68????????           |                     
            //   ff15????????         |                     
            //   c3                   | ret                 
            //   b8????????           |                     
            //   e8????????           |                     
            //   83ec2c               | sub                 esp, 0x2c

        $sequence_9 = { ff742408 e8???????? c20800 8bc1 }
            // n = 4, score = 600
            //   ff742408             | push                dword ptr [esp + 8]
            //   e8????????           |                     
            //   c20800               | ret                 8
            //   8bc1                 | mov                 eax, ecx

        $sequence_10 = { 53 68000000a0 6a03 53 }
            // n = 4, score = 500
            //   53                   | push                ebx
            //   68000000a0           | push                0xa0000000
            //   6a03                 | push                3
            //   53                   | push                ebx

        $sequence_11 = { 55 56 57 6880020000 }
            // n = 4, score = 500
            //   55                   | push                ebp
            //   56                   | push                esi
            //   57                   | push                edi
            //   6880020000           | push                0x280

        $sequence_12 = { 7508 83c8ff e9???????? 8b839f830000 }
            // n = 4, score = 500
            //   7508                 | jne                 0xa
            //   83c8ff               | or                  eax, 0xffffffff
            //   e9????????           |                     
            //   8b839f830000         | mov                 eax, dword ptr [ebx + 0x839f]

        $sequence_13 = { 7507 b800308000 eb02 33c0 }
            // n = 4, score = 500
            //   7507                 | jne                 9
            //   b800308000           | mov                 eax, 0x803000
            //   eb02                 | jmp                 4
            //   33c0                 | xor                 eax, eax

        $sequence_14 = { 5b c3 55 8bec 833d????????00 53 56 }
            // n = 7, score = 500
            //   5b                   | pop                 ebx
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   833d????????00       |                     
            //   53                   | push                ebx
            //   56                   | push                esi

        $sequence_15 = { 6a01 03c3 68???????? 50 e8???????? 83c40c 85c0 }
            // n = 7, score = 500
            //   6a01                 | push                1
            //   03c3                 | add                 eax, ebx
            //   68????????           |                     
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   85c0                 | test                eax, eax

        $sequence_16 = { 75dd 57 e8???????? 59 }
            // n = 4, score = 500
            //   75dd                 | jne                 0xffffffdf
            //   57                   | push                edi
            //   e8????????           |                     
            //   59                   | pop                 ecx

        $sequence_17 = { 50 e8???????? 59 8b4e2c }
            // n = 4, score = 400
            //   50                   | push                eax
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   8b4e2c               | mov                 ecx, dword ptr [esi + 0x2c]

        $sequence_18 = { e8???????? 59 eb57 53 }
            // n = 4, score = 400
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   eb57                 | jmp                 0x59
            //   53                   | push                ebx

        $sequence_19 = { 0245fd 3245fe 8a4dff d2c8 }
            // n = 4, score = 400
            //   0245fd               | add                 al, byte ptr [ebp - 3]
            //   3245fe               | xor                 al, byte ptr [ebp - 2]
            //   8a4dff               | mov                 cl, byte ptr [ebp - 1]
            //   d2c8                 | ror                 al, cl

        $sequence_20 = { 85ff 7e23 8b414c 897c2410 83c004 8b08 03d1 }
            // n = 7, score = 400
            //   85ff                 | test                edi, edi
            //   7e23                 | jle                 0x25
            //   8b414c               | mov                 eax, dword ptr [ecx + 0x4c]
            //   897c2410             | mov                 dword ptr [esp + 0x10], edi
            //   83c004               | add                 eax, 4
            //   8b08                 | mov                 ecx, dword ptr [eax]
            //   03d1                 | add                 edx, ecx

        $sequence_21 = { 016c242c 8b44242c 5f 5e 5d }
            // n = 5, score = 400
            //   016c242c             | add                 dword ptr [esp + 0x2c], ebp
            //   8b44242c             | mov                 eax, dword ptr [esp + 0x2c]
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp

        $sequence_22 = { 0175fc 8b75f8 46 8975f8 3b75f4 }
            // n = 5, score = 300
            //   0175fc               | add                 dword ptr [ebp - 4], esi
            //   8b75f8               | mov                 esi, dword ptr [ebp - 8]
            //   46                   | inc                 esi
            //   8975f8               | mov                 dword ptr [ebp - 8], esi
            //   3b75f4               | cmp                 esi, dword ptr [ebp - 0xc]

        $sequence_23 = { 017dfc 3bb188000000 75a4 5f }
            // n = 4, score = 300
            //   017dfc               | add                 dword ptr [ebp - 4], edi
            //   3bb188000000         | cmp                 esi, dword ptr [ecx + 0x88]
            //   75a4                 | jne                 0xffffffa6
            //   5f                   | pop                 edi

        $sequence_24 = { 02c1 8845e9 8a45ee 80e30f }
            // n = 4, score = 300
            //   02c1                 | add                 al, cl
            //   8845e9               | mov                 byte ptr [ebp - 0x17], al
            //   8a45ee               | mov                 al, byte ptr [ebp - 0x12]
            //   80e30f               | and                 bl, 0xf

        $sequence_25 = { 02c1 8845ea 8a45ee 243f }
            // n = 4, score = 300
            //   02c1                 | add                 al, cl
            //   8845ea               | mov                 byte ptr [ebp - 0x16], al
            //   8a45ee               | mov                 al, byte ptr [ebp - 0x12]
            //   243f                 | and                 al, 0x3f

        $sequence_26 = { 6a00 53 56 8b06 }
            // n = 4, score = 200
            //   6a00                 | push                0
            //   53                   | push                ebx
            //   56                   | push                esi
            //   8b06                 | mov                 eax, dword ptr [esi]

        $sequence_27 = { 6a00 8b9580faffff 837a3000 750b 8b8db4f9ffff 83c904 }
            // n = 6, score = 200
            //   6a00                 | push                0
            //   8b9580faffff         | mov                 edx, dword ptr [ebp - 0x580]
            //   837a3000             | cmp                 dword ptr [edx + 0x30], 0
            //   750b                 | jne                 0xd
            //   8b8db4f9ffff         | mov                 ecx, dword ptr [ebp - 0x64c]
            //   83c904               | or                  ecx, 4

        $sequence_28 = { 6a00 53 57 8b07 }
            // n = 4, score = 200
            //   6a00                 | push                0
            //   53                   | push                ebx
            //   57                   | push                edi
            //   8b07                 | mov                 eax, dword ptr [edi]

    condition:
        7 of them and filesize < 2220032
}