rule win_swen_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.swen."
        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.swen"
        malpedia_rule_date = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { 89b5a0feffff 83cbff 3bf3 742a 8d45e4 50 }
            // n = 6, score = 100
            //   89b5a0feffff         | mov                 dword ptr [ebp - 0x160], esi
            //   83cbff               | or                  ebx, 0xffffffff
            //   3bf3                 | cmp                 esi, ebx
            //   742a                 | je                  0x2c
            //   8d45e4               | lea                 eax, [ebp - 0x1c]
            //   50                   | push                eax

        $sequence_1 = { 741d 68???????? 57 68???????? 68???????? 6802000080 e8???????? }
            // n = 7, score = 100
            //   741d                 | je                  0x1f
            //   68????????           |                     
            //   57                   | push                edi
            //   68????????           |                     
            //   68????????           |                     
            //   6802000080           | push                0x80000002
            //   e8????????           |                     

        $sequence_2 = { 7514 8365cc00 46 8975dc c6041e0d 46 8975dc }
            // n = 7, score = 100
            //   7514                 | jne                 0x16
            //   8365cc00             | and                 dword ptr [ebp - 0x34], 0
            //   46                   | inc                 esi
            //   8975dc               | mov                 dword ptr [ebp - 0x24], esi
            //   c6041e0d             | mov                 byte ptr [esi + ebx], 0xd
            //   46                   | inc                 esi
            //   8975dc               | mov                 dword ptr [ebp - 0x24], esi

        $sequence_3 = { 50 e8???????? 68???????? 8d857cfeffff 50 }
            // n = 5, score = 100
            //   50                   | push                eax
            //   e8????????           |                     
            //   68????????           |                     
            //   8d857cfeffff         | lea                 eax, [ebp - 0x184]
            //   50                   | push                eax

        $sequence_4 = { 8d8520ffffff 50 68???????? e8???????? 8d85bcfeffff 50 56 }
            // n = 7, score = 100
            //   8d8520ffffff         | lea                 eax, [ebp - 0xe0]
            //   50                   | push                eax
            //   68????????           |                     
            //   e8????????           |                     
            //   8d85bcfeffff         | lea                 eax, [ebp - 0x144]
            //   50                   | push                eax
            //   56                   | push                esi

        $sequence_5 = { e8???????? 50 ffb5e8f5ffff 8d8514ffffff 50 8b8568f9ffff f7d8 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   50                   | push                eax
            //   ffb5e8f5ffff         | push                dword ptr [ebp - 0xa18]
            //   8d8514ffffff         | lea                 eax, [ebp - 0xec]
            //   50                   | push                eax
            //   8b8568f9ffff         | mov                 eax, dword ptr [ebp - 0x698]
            //   f7d8                 | neg                 eax

        $sequence_6 = { 50 8b3d???????? ffd7 83c40c 6a00 6880000000 }
            // n = 6, score = 100
            //   50                   | push                eax
            //   8b3d????????         |                     
            //   ffd7                 | call                edi
            //   83c40c               | add                 esp, 0xc
            //   6a00                 | push                0
            //   6880000000           | push                0x80

        $sequence_7 = { 33f6 8975fc 3935???????? 0f854d010000 3935???????? 7543 c705????????01000000 }
            // n = 7, score = 100
            //   33f6                 | xor                 esi, esi
            //   8975fc               | mov                 dword ptr [ebp - 4], esi
            //   3935????????         |                     
            //   0f854d010000         | jne                 0x153
            //   3935????????         |                     
            //   7543                 | jne                 0x45
            //   c705????????01000000     |     

        $sequence_8 = { 8d85a4feffff 50 ffb5a0feffff ff15???????? ffb5a0feffff ff15???????? 8d8574ffffff }
            // n = 7, score = 100
            //   8d85a4feffff         | lea                 eax, [ebp - 0x15c]
            //   50                   | push                eax
            //   ffb5a0feffff         | push                dword ptr [ebp - 0x160]
            //   ff15????????         |                     
            //   ffb5a0feffff         | push                dword ptr [ebp - 0x160]
            //   ff15????????         |                     
            //   8d8574ffffff         | lea                 eax, [ebp - 0x8c]

        $sequence_9 = { 8b4508 8818 395908 7506 834dfcff eb53 8b01 }
            // n = 7, score = 100
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   8818                 | mov                 byte ptr [eax], bl
            //   395908               | cmp                 dword ptr [ecx + 8], ebx
            //   7506                 | jne                 8
            //   834dfcff             | or                  dword ptr [ebp - 4], 0xffffffff
            //   eb53                 | jmp                 0x55
            //   8b01                 | mov                 eax, dword ptr [ecx]

    condition:
        7 of them and filesize < 286720
}