rule win_lockbit_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.lockbit."
        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.lockbit"
        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 = { 33d0 8bc1 c1e810 0fb6c0 c1e208 }
            // n = 5, score = 300
            //   33d0                 | xor                 edx, eax
            //   8bc1                 | mov                 eax, ecx
            //   c1e810               | shr                 eax, 0x10
            //   0fb6c0               | movzx               eax, al
            //   c1e208               | shl                 edx, 8

        $sequence_1 = { 66ad 90 6683f841 720b 6683f85a 7705 }
            // n = 6, score = 300
            //   66ad                 | lodsw               ax, word ptr [esi]
            //   90                   | nop                 
            //   6683f841             | cmp                 ax, 0x41
            //   720b                 | jb                  0xd
            //   6683f85a             | cmp                 ax, 0x5a
            //   7705                 | ja                  7

        $sequence_2 = { 6a00 6a00 6800000040 ff75d4 }
            // n = 4, score = 300
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   6800000040           | push                0x40000000
            //   ff75d4               | push                dword ptr [ebp - 0x2c]

        $sequence_3 = { 5e 5a 59 5d }
            // n = 4, score = 300
            //   5e                   | pop                 esi
            //   5a                   | pop                 edx
            //   59                   | pop                 ecx
            //   5d                   | pop                 ebp

        $sequence_4 = { 8d8550fdffff 50 6a00 ff15???????? }
            // n = 4, score = 300
            //   8d8550fdffff         | lea                 eax, [ebp - 0x2b0]
            //   50                   | push                eax
            //   6a00                 | push                0
            //   ff15????????         |                     

        $sequence_5 = { be40000000 55 8b6d10 8bc1 33d2 f7f6 8ac1 }
            // n = 7, score = 300
            //   be40000000           | mov                 esi, 0x40
            //   55                   | push                ebp
            //   8b6d10               | mov                 ebp, dword ptr [ebp + 0x10]
            //   8bc1                 | mov                 eax, ecx
            //   33d2                 | xor                 edx, edx
            //   f7f6                 | div                 esi
            //   8ac1                 | mov                 al, cl

        $sequence_6 = { 89570c f745f800000002 740c 5f }
            // n = 4, score = 300
            //   89570c               | mov                 dword ptr [edi + 0xc], edx
            //   f745f800000002       | test                dword ptr [ebp - 8], 0x2000000
            //   740c                 | je                  0xe
            //   5f                   | pop                 edi

        $sequence_7 = { 660f73f904 660fefc8 0f28c1 660f73f804 660fefc1 }
            // n = 5, score = 300
            //   660f73f904           | pslldq              xmm1, 4
            //   660fefc8             | pxor                xmm1, xmm0
            //   0f28c1               | movaps              xmm0, xmm1
            //   660f73f804           | pslldq              xmm0, 4
            //   660fefc1             | pxor                xmm0, xmm1

        $sequence_8 = { d3ca 03d0 90 85c0 75d8 }
            // n = 5, score = 300
            //   d3ca                 | ror                 edx, cl
            //   03d0                 | add                 edx, eax
            //   90                   | nop                 
            //   85c0                 | test                eax, eax
            //   75d8                 | jne                 0xffffffda

        $sequence_9 = { 41 81f900030000 75d6 5d 8bc3 5f 5e }
            // n = 7, score = 300
            //   41                   | inc                 ecx
            //   81f900030000         | cmp                 ecx, 0x300
            //   75d6                 | jne                 0xffffffd8
            //   5d                   | pop                 ebp
            //   8bc3                 | mov                 eax, ebx
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi

        $sequence_10 = { 6a02 ff750c ff7508 6a00 }
            // n = 4, score = 300
            //   6a02                 | push                2
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   ff7508               | push                dword ptr [ebp + 8]
            //   6a00                 | push                0

        $sequence_11 = { 6685c0 7505 e9???????? 6683f841 }
            // n = 4, score = 300
            //   6685c0               | test                ax, ax
            //   7505                 | jne                 7
            //   e9????????           |                     
            //   6683f841             | cmp                 ax, 0x41

        $sequence_12 = { 33c0 8b550c 8b7508 b961000000 66ad 90 6683f841 }
            // n = 7, score = 300
            //   33c0                 | xor                 eax, eax
            //   8b550c               | mov                 edx, dword ptr [ebp + 0xc]
            //   8b7508               | mov                 esi, dword ptr [ebp + 8]
            //   b961000000           | mov                 ecx, 0x61
            //   66ad                 | lodsw               ax, word ptr [esi]
            //   90                   | nop                 
            //   6683f841             | cmp                 ax, 0x41

        $sequence_13 = { 8d7df0 33c9 53 0fa2 8bf3 }
            // n = 5, score = 300
            //   8d7df0               | lea                 edi, [ebp - 0x10]
            //   33c9                 | xor                 ecx, ecx
            //   53                   | push                ebx
            //   0fa2                 | cpuid               
            //   8bf3                 | mov                 esi, ebx

        $sequence_14 = { 8b7d08 85f6 7433 55 8b6d10 8a540d00 }
            // n = 6, score = 300
            //   8b7d08               | mov                 edi, dword ptr [ebp + 8]
            //   85f6                 | test                esi, esi
            //   7433                 | je                  0x35
            //   55                   | push                ebp
            //   8b6d10               | mov                 ebp, dword ptr [ebp + 0x10]
            //   8a540d00             | mov                 dl, byte ptr [ebp + ecx]

        $sequence_15 = { 897704 894f08 89570c f745f800000002 }
            // n = 4, score = 300
            //   897704               | mov                 dword ptr [edi + 4], esi
            //   894f08               | mov                 dword ptr [edi + 8], ecx
            //   89570c               | mov                 dword ptr [edi + 0xc], edx
            //   f745f800000002       | test                dword ptr [ebp - 8], 0x2000000

        $sequence_16 = { 8d45f8 50 8d45fc 50 ff75fc ff75f4 }
            // n = 6, score = 300
            //   8d45f8               | lea                 eax, [ebp - 8]
            //   50                   | push                eax
            //   8d45fc               | lea                 eax, [ebp - 4]
            //   50                   | push                eax
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   ff75f4               | push                dword ptr [ebp - 0xc]

        $sequence_17 = { 83ec10 53 56 57 33c0 8d7df0 33c9 }
            // n = 7, score = 300
            //   83ec10               | sub                 esp, 0x10
            //   53                   | push                ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   33c0                 | xor                 eax, eax
            //   8d7df0               | lea                 edi, [ebp - 0x10]
            //   33c9                 | xor                 ecx, ecx

    condition:
        7 of them and filesize < 2049024
}