rule win_joao_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.joao."
        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.joao"
        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 = { 68???????? 8d4dd4 e8???????? 8d4dd0 }
            // n = 4, score = 400
            //   68????????           |                     
            //   8d4dd4               | lea                 ecx, [ebp - 0x2c]
            //   e8????????           |                     
            //   8d4dd0               | lea                 ecx, [ebp - 0x30]

        $sequence_1 = { 8bff 85db 7409 83f8ff 7576 834de801 }
            // n = 6, score = 400
            //   8bff                 | mov                 edi, edi
            //   85db                 | test                ebx, ebx
            //   7409                 | je                  0xb
            //   83f8ff               | cmp                 eax, -1
            //   7576                 | jne                 0x78
            //   834de801             | or                  dword ptr [ebp - 0x18], 1

        $sequence_2 = { 8b450c 8b5508 56 8b7510 56 50 52 }
            // n = 7, score = 400
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   8b5508               | mov                 edx, dword ptr [ebp + 8]
            //   56                   | push                esi
            //   8b7510               | mov                 esi, dword ptr [ebp + 0x10]
            //   56                   | push                esi
            //   50                   | push                eax
            //   52                   | push                edx

        $sequence_3 = { 8d4dec 51 6a00 52 ffd0 }
            // n = 5, score = 400
            //   8d4dec               | lea                 ecx, [ebp - 0x14]
            //   51                   | push                ecx
            //   6a00                 | push                0
            //   52                   | push                edx
            //   ffd0                 | call                eax

        $sequence_4 = { 83c40c 85c0 7514 8b45e4 3bc7 }
            // n = 5, score = 400
            //   83c40c               | add                 esp, 0xc
            //   85c0                 | test                eax, eax
            //   7514                 | jne                 0x16
            //   8b45e4               | mov                 eax, dword ptr [ebp - 0x1c]
            //   3bc7                 | cmp                 eax, edi

        $sequence_5 = { 8b31 57 2bc6 bfffffff07 c1f805 2bfa 3bf8 }
            // n = 7, score = 400
            //   8b31                 | mov                 esi, dword ptr [ecx]
            //   57                   | push                edi
            //   2bc6                 | sub                 eax, esi
            //   bfffffff07           | mov                 edi, 0x7ffffff
            //   c1f805               | sar                 eax, 5
            //   2bfa                 | sub                 edi, edx
            //   3bf8                 | cmp                 edi, eax

        $sequence_6 = { 51 e8???????? 83c404 bf07000000 b8???????? }
            // n = 5, score = 400
            //   51                   | push                ecx
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   bf07000000           | mov                 edi, 7
            //   b8????????           |                     

        $sequence_7 = { 52 8bce 897dfc e8???????? 837dc810 }
            // n = 5, score = 400
            //   52                   | push                edx
            //   8bce                 | mov                 ecx, esi
            //   897dfc               | mov                 dword ptr [ebp - 4], edi
            //   e8????????           |                     
            //   837dc810             | cmp                 dword ptr [ebp - 0x38], 0x10

        $sequence_8 = { 83c404 bf09000000 b8???????? 897dd0 }
            // n = 4, score = 400
            //   83c404               | add                 esp, 4
            //   bf09000000           | mov                 edi, 9
            //   b8????????           |                     
            //   897dd0               | mov                 dword ptr [ebp - 0x30], edi

        $sequence_9 = { 8b5210 0fb6c8 f6044a48 0f857bffffff }
            // n = 4, score = 400
            //   8b5210               | mov                 edx, dword ptr [edx + 0x10]
            //   0fb6c8               | movzx               ecx, al
            //   f6044a48             | test                byte ptr [edx + ecx*2], 0x48
            //   0f857bffffff         | jne                 0xffffff81

    condition:
        7 of them and filesize < 2867200
}