rule win_lookback_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.lookback."
        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.lookback"
        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 = { 56 57 b946000000 33c0 }
            // n = 4, score = 200
            //   56                   | push                esi
            //   57                   | push                edi
            //   b946000000           | mov                 ecx, 0x46
            //   33c0                 | xor                 eax, eax

        $sequence_1 = { 85db 0f8482000000 52 ff15???????? 85c0 7477 0fbf480a }
            // n = 7, score = 200
            //   85db                 | test                ebx, ebx
            //   0f8482000000         | je                  0x88
            //   52                   | push                edx
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7477                 | je                  0x79
            //   0fbf480a             | movsx               ecx, word ptr [eax + 0xa]

        $sequence_2 = { e8???????? 3bc7 0f84a1010000 83f8ff 0f8498010000 }
            // n = 5, score = 200
            //   e8????????           |                     
            //   3bc7                 | cmp                 eax, edi
            //   0f84a1010000         | je                  0x1a7
            //   83f8ff               | cmp                 eax, -1
            //   0f8498010000         | je                  0x19e

        $sequence_3 = { 3bef 7511 8b4810 3bcf 0f8493010000 894c241c eb25 }
            // n = 7, score = 200
            //   3bef                 | cmp                 ebp, edi
            //   7511                 | jne                 0x13
            //   8b4810               | mov                 ecx, dword ptr [eax + 0x10]
            //   3bcf                 | cmp                 ecx, edi
            //   0f8493010000         | je                  0x199
            //   894c241c             | mov                 dword ptr [esp + 0x1c], ecx
            //   eb25                 | jmp                 0x27

        $sequence_4 = { ff15???????? 8d542400 52 e8???????? 33c0 81c408010000 c3 }
            // n = 7, score = 200
            //   ff15????????         |                     
            //   8d542400             | lea                 edx, [esp]
            //   52                   | push                edx
            //   e8????????           |                     
            //   33c0                 | xor                 eax, eax
            //   81c408010000         | add                 esp, 0x108
            //   c3                   | ret                 

        $sequence_5 = { 56 8d7c2420 8b32 6a00 c1e902 }
            // n = 5, score = 200
            //   56                   | push                esi
            //   8d7c2420             | lea                 edi, [esp + 0x20]
            //   8b32                 | mov                 esi, dword ptr [edx]
            //   6a00                 | push                0
            //   c1e902               | shr                 ecx, 2

        $sequence_6 = { 8d5108 d1e8 85c0 7e33 }
            // n = 4, score = 200
            //   8d5108               | lea                 edx, [ecx + 8]
            //   d1e8                 | shr                 eax, 1
            //   85c0                 | test                eax, eax
            //   7e33                 | jle                 0x35

        $sequence_7 = { 7446 83b89001000006 7514 b903000000 8bfd 8db094010000 }
            // n = 6, score = 200
            //   7446                 | je                  0x48
            //   83b89001000006       | cmp                 dword ptr [eax + 0x190], 6
            //   7514                 | jne                 0x16
            //   b903000000           | mov                 ecx, 3
            //   8bfd                 | mov                 edi, ebp
            //   8db094010000         | lea                 esi, [eax + 0x194]

        $sequence_8 = { 66396b06 7636 8d930c010000 8b32 }
            // n = 4, score = 200
            //   66396b06             | cmp                 word ptr [ebx + 6], bp
            //   7636                 | jbe                 0x38
            //   8d930c010000         | lea                 edx, [ebx + 0x10c]
            //   8b32                 | mov                 esi, dword ptr [edx]

        $sequence_9 = { 7422 6a00 8d4c2404 6a20 51 6a03 }
            // n = 6, score = 200
            //   7422                 | je                  0x24
            //   6a00                 | push                0
            //   8d4c2404             | lea                 ecx, [esp + 4]
            //   6a20                 | push                0x20
            //   51                   | push                ecx
            //   6a03                 | push                3

    condition:
        7 of them and filesize < 131072
}