rule win_klrd_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-06-10"
        version = "1"
        description = "Detects win.klrd."
        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.klrd"
        malpedia_rule_date = "20210604"
        malpedia_hash = "be09d5d71e77373c0f538068be31a2ad4c69cfbd"
        malpedia_version = "20210616"
        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 56 56 68???????? 56 56 8975fc }
            // n = 7, score = 100
            //   50                   | push                eax
            //   56                   | push                esi
            //   56                   | push                esi
            //   68????????           |                     
            //   56                   | push                esi
            //   56                   | push                esi
            //   8975fc               | mov                 dword ptr [ebp - 4], esi

        $sequence_1 = { eb59 ffb5bcfdffff 6a01 8d85c4feffff 50 8d85c0fdffff 50 }
            // n = 7, score = 100
            //   eb59                 | jmp                 0x5b
            //   ffb5bcfdffff         | push                dword ptr [ebp - 0x244]
            //   6a01                 | push                1
            //   8d85c4feffff         | lea                 eax, dword ptr [ebp - 0x13c]
            //   50                   | push                eax
            //   8d85c0fdffff         | lea                 eax, dword ptr [ebp - 0x240]
            //   50                   | push                eax

        $sequence_2 = { 68ff000000 6a00 8d85b9fcffff 50 e8???????? }
            // n = 5, score = 100
            //   68ff000000           | push                0xff
            //   6a00                 | push                0
            //   8d85b9fcffff         | lea                 eax, dword ptr [ebp - 0x347]
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_3 = { 83bdd4feffff00 7502 eb26 0fb785c4feffff }
            // n = 4, score = 100
            //   83bdd4feffff00       | cmp                 dword ptr [ebp - 0x12c], 0
            //   7502                 | jne                 4
            //   eb26                 | jmp                 0x28
            //   0fb785c4feffff       | movzx               eax, word ptr [ebp - 0x13c]

        $sequence_4 = { 8d85fcefffff 33f6 50 8975fc ff15???????? }
            // n = 5, score = 100
            //   8d85fcefffff         | lea                 eax, dword ptr [ebp - 0x1004]
            //   33f6                 | xor                 esi, esi
            //   50                   | push                eax
            //   8975fc               | mov                 dword ptr [ebp - 4], esi
            //   ff15????????         |                     

        $sequence_5 = { eb26 0fb785c4feffff 25ff000000 8885b7fcffff 0fbe85b7fcffff 50 }
            // n = 6, score = 100
            //   eb26                 | jmp                 0x28
            //   0fb785c4feffff       | movzx               eax, word ptr [ebp - 0x13c]
            //   25ff000000           | and                 eax, 0xff
            //   8885b7fcffff         | mov                 byte ptr [ebp - 0x349], al
            //   0fbe85b7fcffff       | movsx               eax, byte ptr [ebp - 0x349]
            //   50                   | push                eax

        $sequence_6 = { 8d85e8feffff 50 68???????? e8???????? 59 59 ff15???????? }
            // n = 7, score = 100
            //   8d85e8feffff         | lea                 eax, dword ptr [ebp - 0x118]
            //   50                   | push                eax
            //   68????????           |                     
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx
            //   ff15????????         |                     

        $sequence_7 = { 8d85fdfeffff 53 50 889dfcfeffff e8???????? 83c40c 53 }
            // n = 7, score = 100
            //   8d85fdfeffff         | lea                 eax, dword ptr [ebp - 0x103]
            //   53                   | push                ebx
            //   50                   | push                eax
            //   889dfcfeffff         | mov                 byte ptr [ebp - 0x104], bl
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   53                   | push                ebx

        $sequence_8 = { ffb5b0fcffff ff15???????? 8985c8feffff 83bdc8feffff00 7515 ff15???????? }
            // n = 6, score = 100
            //   ffb5b0fcffff         | push                dword ptr [ebp - 0x350]
            //   ff15????????         |                     
            //   8985c8feffff         | mov                 dword ptr [ebp - 0x138], eax
            //   83bdc8feffff00       | cmp                 dword ptr [ebp - 0x138], 0
            //   7515                 | jne                 0x17
            //   ff15????????         |                     

        $sequence_9 = { 59 59 ff15???????? 8985b0fcffff }
            // n = 4, score = 100
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx
            //   ff15????????         |                     
            //   8985b0fcffff         | mov                 dword ptr [ebp - 0x350], eax

    condition:
        7 of them and filesize < 40960
}