rule win_jaff_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.jaff."
        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.jaff"
        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 = { 50 6a08 894e04 897e08 }
            // n = 4, score = 600
            //   50                   | push                eax
            //   6a08                 | push                8
            //   894e04               | mov                 dword ptr [esi + 4], ecx
            //   897e08               | mov                 dword ptr [esi + 8], edi

        $sequence_1 = { ffd7 8b55d8 52 6a00 ffd3 }
            // n = 5, score = 600
            //   ffd7                 | call                edi
            //   8b55d8               | mov                 edx, dword ptr [ebp - 0x28]
            //   52                   | push                edx
            //   6a00                 | push                0
            //   ffd3                 | call                ebx

        $sequence_2 = { 6a01 56 ff15???????? 8b45f8 }
            // n = 4, score = 600
            //   6a01                 | push                1
            //   56                   | push                esi
            //   ff15????????         |                     
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]

        $sequence_3 = { 50 ff15???????? 85db 746a }
            // n = 4, score = 600
            //   50                   | push                eax
            //   ff15????????         |                     
            //   85db                 | test                ebx, ebx
            //   746a                 | je                  0x6c

        $sequence_4 = { 47 83c40c 4e 83ff29 7cd6 017df8 395df4 }
            // n = 7, score = 600
            //   47                   | inc                 edi
            //   83c40c               | add                 esp, 0xc
            //   4e                   | dec                 esi
            //   83ff29               | cmp                 edi, 0x29
            //   7cd6                 | jl                  0xffffffd8
            //   017df8               | add                 dword ptr [ebp - 8], edi
            //   395df4               | cmp                 dword ptr [ebp - 0xc], ebx

        $sequence_5 = { 8d8570fbffff 68???????? 33f6 50 8975e8 c645f001 c645fd00 }
            // n = 7, score = 600
            //   8d8570fbffff         | lea                 eax, [ebp - 0x490]
            //   68????????           |                     
            //   33f6                 | xor                 esi, esi
            //   50                   | push                eax
            //   8975e8               | mov                 dword ptr [ebp - 0x18], esi
            //   c645f001             | mov                 byte ptr [ebp - 0x10], 1
            //   c645fd00             | mov                 byte ptr [ebp - 3], 0

        $sequence_6 = { 72ed 8b45e8 50 6a00 ffd3 }
            // n = 5, score = 600
            //   72ed                 | jb                  0xffffffef
            //   8b45e8               | mov                 eax, dword ptr [ebp - 0x18]
            //   50                   | push                eax
            //   6a00                 | push                0
            //   ffd3                 | call                ebx

        $sequence_7 = { 6a08 ff15???????? 50 ff15???????? 8bd8 85db 743c }
            // n = 7, score = 600
            //   6a08                 | push                8
            //   ff15????????         |                     
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8bd8                 | mov                 ebx, eax
            //   85db                 | test                ebx, ebx
            //   743c                 | je                  0x3e

        $sequence_8 = { 85f6 7419 33c0 0fb7d0 8bc2 c1e210 0bc2 }
            // n = 7, score = 600
            //   85f6                 | test                esi, esi
            //   7419                 | je                  0x1b
            //   33c0                 | xor                 eax, eax
            //   0fb7d0               | movzx               edx, ax
            //   8bc2                 | mov                 eax, edx
            //   c1e210               | shl                 edx, 0x10
            //   0bc2                 | or                  eax, edx

        $sequence_9 = { 8b4508 8b7804 8d043f 50 6a08 c745c800000000 }
            // n = 6, score = 600
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   8b7804               | mov                 edi, dword ptr [eax + 4]
            //   8d043f               | lea                 eax, [edi + edi]
            //   50                   | push                eax
            //   6a08                 | push                8
            //   c745c800000000       | mov                 dword ptr [ebp - 0x38], 0

    condition:
        7 of them and filesize < 106496
}