rule win_nymaim2_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.nymaim2."
        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.nymaim2"
        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 = { 037704 8d450c 50 8bce e8???????? 834dfcff 8d4d0c }
            // n = 7, score = 200
            //   037704               | add                 esi, dword ptr [edi + 4]
            //   8d450c               | lea                 eax, [ebp + 0xc]
            //   50                   | push                eax
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   834dfcff             | or                  dword ptr [ebp - 4], 0xffffffff
            //   8d4d0c               | lea                 ecx, [ebp + 0xc]

        $sequence_1 = { 6806020000 8d8d6cffffff e8???????? ff762c 8bc8 897dfc e8???????? }
            // n = 7, score = 200
            //   6806020000           | push                0x206
            //   8d8d6cffffff         | lea                 ecx, [ebp - 0x94]
            //   e8????????           |                     
            //   ff762c               | push                dword ptr [esi + 0x2c]
            //   8bc8                 | mov                 ecx, eax
            //   897dfc               | mov                 dword ptr [ebp - 4], edi
            //   e8????????           |                     

        $sequence_2 = { 0fb6c0 8d4b04 8945f4 894dfc 8b4dfc e8???????? 84c0 }
            // n = 7, score = 200
            //   0fb6c0               | movzx               eax, al
            //   8d4b04               | lea                 ecx, [ebx + 4]
            //   8945f4               | mov                 dword ptr [ebp - 0xc], eax
            //   894dfc               | mov                 dword ptr [ebp - 4], ecx
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   e8????????           |                     
            //   84c0                 | test                al, al

        $sequence_3 = { 89460c 8bc6 5f 5e 5b c20400 b8???????? }
            // n = 7, score = 200
            //   89460c               | mov                 dword ptr [esi + 0xc], eax
            //   8bc6                 | mov                 eax, esi
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx
            //   c20400               | ret                 4
            //   b8????????           |                     

        $sequence_4 = { 8b4d10 50 e8???????? 50 ff15???????? 50 ff15???????? }
            // n = 7, score = 200
            //   8b4d10               | mov                 ecx, dword ptr [ebp + 0x10]
            //   50                   | push                eax
            //   e8????????           |                     
            //   50                   | push                eax
            //   ff15????????         |                     
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_5 = { 50 e8???????? 59 8d45f0 50 e8???????? 6a01 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   8d45f0               | lea                 eax, [ebp - 0x10]
            //   50                   | push                eax
            //   e8????????           |                     
            //   6a01                 | push                1

        $sequence_6 = { c706???????? 8365fc00 8d4e08 e8???????? 834dfcff 8d4e04 e8???????? }
            // n = 7, score = 200
            //   c706????????         |                     
            //   8365fc00             | and                 dword ptr [ebp - 4], 0
            //   8d4e08               | lea                 ecx, [esi + 8]
            //   e8????????           |                     
            //   834dfcff             | or                  dword ptr [ebp - 4], 0xffffffff
            //   8d4e04               | lea                 ecx, [esi + 4]
            //   e8????????           |                     

        $sequence_7 = { 75f5 33c0 8a23 894514 8b4518 48 83f803 }
            // n = 7, score = 200
            //   75f5                 | jne                 0xfffffff7
            //   33c0                 | xor                 eax, eax
            //   8a23                 | mov                 ah, byte ptr [ebx]
            //   894514               | mov                 dword ptr [ebp + 0x14], eax
            //   8b4518               | mov                 eax, dword ptr [ebp + 0x18]
            //   48                   | dec                 eax
            //   83f803               | cmp                 eax, 3

        $sequence_8 = { ff15???????? ff36 8d45d4 8bcb c645fc04 }
            // n = 5, score = 200
            //   ff15????????         |                     
            //   ff36                 | push                dword ptr [esi]
            //   8d45d4               | lea                 eax, [ebp - 0x2c]
            //   8bcb                 | mov                 ecx, ebx
            //   c645fc04             | mov                 byte ptr [ebp - 4], 4

        $sequence_9 = { 834dfcff 89770c 5e 8b450c 8b4d08 85c0 7608 }
            // n = 7, score = 200
            //   834dfcff             | or                  dword ptr [ebp - 4], 0xffffffff
            //   89770c               | mov                 dword ptr [edi + 0xc], esi
            //   5e                   | pop                 esi
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   85c0                 | test                eax, eax
            //   7608                 | jbe                 0xa

    condition:
        7 of them and filesize < 753664
}