rule win_penco_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.penco."
        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.penco"
        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 = { 81ff00000040 774e 83c740 6a04 6800300000 57 6a00 }
            // n = 7, score = 100
            //   81ff00000040         | cmp                 edi, 0x40000000
            //   774e                 | ja                  0x50
            //   83c740               | add                 edi, 0x40
            //   6a04                 | push                4
            //   6800300000           | push                0x3000
            //   57                   | push                edi
            //   6a00                 | push                0

        $sequence_1 = { 895054 89705c 8bce c1e910 0fb6d1 8b0c9500d03400 }
            // n = 6, score = 100
            //   895054               | mov                 dword ptr [eax + 0x54], edx
            //   89705c               | mov                 dword ptr [eax + 0x5c], esi
            //   8bce                 | mov                 ecx, esi
            //   c1e910               | shr                 ecx, 0x10
            //   0fb6d1               | movzx               edx, cl
            //   8b0c9500d03400       | mov                 ecx, dword ptr [edx*4 + 0x34d000]

        $sequence_2 = { 7cf3 3bc8 7405 45 3bee 7eda }
            // n = 6, score = 100
            //   7cf3                 | jl                  0xfffffff5
            //   3bc8                 | cmp                 ecx, eax
            //   7405                 | je                  7
            //   45                   | inc                 ebp
            //   3bee                 | cmp                 ebp, esi
            //   7eda                 | jle                 0xffffffdc

        $sequence_3 = { 8b4510 8b8848030000 51 e8???????? 83c410 8985bcfdffff }
            // n = 6, score = 100
            //   8b4510               | mov                 eax, dword ptr [ebp + 0x10]
            //   8b8848030000         | mov                 ecx, dword ptr [eax + 0x348]
            //   51                   | push                ecx
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   8985bcfdffff         | mov                 dword ptr [ebp - 0x244], eax

        $sequence_4 = { 7e17 8b542414 8d3c2a 8d4900 8a140f 3a1419 7505 }
            // n = 7, score = 100
            //   7e17                 | jle                 0x19
            //   8b542414             | mov                 edx, dword ptr [esp + 0x14]
            //   8d3c2a               | lea                 edi, [edx + ebp]
            //   8d4900               | lea                 ecx, [ecx]
            //   8a140f               | mov                 dl, byte ptr [edi + ecx]
            //   3a1419               | cmp                 dl, byte ptr [ecx + ebx]
            //   7505                 | jne                 7

        $sequence_5 = { 51 ffd7 53 6800000008 6a03 53 6a01 }
            // n = 7, score = 100
            //   51                   | push                ecx
            //   ffd7                 | call                edi
            //   53                   | push                ebx
            //   6800000008           | push                0x8000000
            //   6a03                 | push                3
            //   53                   | push                ebx
            //   6a01                 | push                1

        $sequence_6 = { 68ff010000 6a00 8d8dd9fdffff 51 e8???????? 83c40c c785b0fdffff00000000 }
            // n = 7, score = 100
            //   68ff010000           | push                0x1ff
            //   6a00                 | push                0
            //   8d8dd9fdffff         | lea                 ecx, [ebp - 0x227]
            //   51                   | push                ecx
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   c785b0fdffff00000000     | mov    dword ptr [ebp - 0x250], 0

        $sequence_7 = { 83c404 3bdd 7518 8d043e 68???????? 50 e8???????? }
            // n = 7, score = 100
            //   83c404               | add                 esp, 4
            //   3bdd                 | cmp                 ebx, ebp
            //   7518                 | jne                 0x1a
            //   8d043e               | lea                 eax, [esi + edi]
            //   68????????           |                     
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_8 = { ff15???????? 8985d0f0ffff e9???????? c785d0fdffff04000000 6a00 8d85d0fdffff 50 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   8985d0f0ffff         | mov                 dword ptr [ebp - 0xf30], eax
            //   e9????????           |                     
            //   c785d0fdffff04000000     | mov    dword ptr [ebp - 0x230], 4
            //   6a00                 | push                0
            //   8d85d0fdffff         | lea                 eax, [ebp - 0x230]
            //   50                   | push                eax

        $sequence_9 = { 750f c7851c94ffff00000000 e9???????? c78554beffff00000000 eb0f 8b8554beffff 83c001 }
            // n = 7, score = 100
            //   750f                 | jne                 0x11
            //   c7851c94ffff00000000     | mov    dword ptr [ebp - 0x6be4], 0
            //   e9????????           |                     
            //   c78554beffff00000000     | mov    dword ptr [ebp - 0x41ac], 0
            //   eb0f                 | jmp                 0x11
            //   8b8554beffff         | mov                 eax, dword ptr [ebp - 0x41ac]
            //   83c001               | add                 eax, 1

    condition:
        7 of them and filesize < 319488
}