rule elf_blackcat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-10-07"
        version = "1"
        description = "Detects elf.blackcat."
        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/elf.blackcat"
        malpedia_rule_date = "20221007"
        malpedia_hash = "597f9539014e3d0f350c069cd804aa71679486ae"
        malpedia_version = "20221010"
        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 = { 69c0???????? c1e811 6bf064 29f2 }
            // n = 4, score = 200
            //   69c0????????         |                     
            //   c1e811               | dec                 esp
            //   6bf064               | mov                 edi, ebp
            //   29f2                 | movaps              xmm0, xmmword ptr [esp + 0x10]

        $sequence_1 = { 81f9???????? 7227 b803000000 81f9???????? 721a b804000000 }
            // n = 6, score = 200
            //   81f9????????         |                     
            //   7227                 | xor                 edx, 0x646f7261
            //   b803000000           | mov                 dword ptr [esp + 0x48], ecx
            //   81f9????????         |                     
            //   721a                 | mov                 ecx, edx
            //   b804000000           | xor                 eax, 0x6e646f6d

        $sequence_2 = { b808000000 e9???????? b809000000 e9???????? b8???????? e9???????? b8???????? }
            // n = 7, score = 200
            //   b808000000           | jmp                 0x3f
            //   e9????????           |                     
            //   b809000000           | dec                 ecx
            //   e9????????           |                     
            //   b8????????           |                     
            //   e9????????           |                     
            //   b8????????           |                     

        $sequence_3 = { e8???????? 0f0b 90 90 55 53 }
            // n = 6, score = 200
            //   e8????????           |                     
            //   0f0b                 | mov                 ecx, ebp
            //   90                   | mov                 edx, edi
            //   90                   | lea                 eax, [ebx - 0x31a0]
            //   55                   | ud2                 
            //   53                   | mov                 ebx, dword ptr [esp + 8]

        $sequence_4 = { 0fb7ca c1e902 69c9???????? c1e911 }
            // n = 4, score = 200
            //   0fb7ca               | shld                esi, edx, 8
            //   c1e902               | shl                 edx, 8
            //   69c9????????         |                     
            //   c1e911               | mov                 ebp, dword ptr [esp + 0x54]

        $sequence_5 = { 721a b804000000 81f9???????? 720d b805000000 81f9ffffff0f }
            // n = 6, score = 200
            //   721a                 | dec                 eax
            //   b804000000           | mov                 edi, dword ptr [esp + 0x270]
            //   81f9????????         |                     
            //   720d                 | cmp                 dword ptr [esp + 0x2f8], 2
            //   b805000000           | jb                  0x8c8
            //   81f9ffffff0f         | dec                 esp

        $sequence_6 = { 83f826 0f95c1 83f801 0f95c0 20c8 }
            // n = 5, score = 200
            //   83f826               | cmp                 eax, 5
            //   0f95c1               | jb                  0x1dba
            //   83f801               | mov                 eax, dword ptr [esp + 0xdc]
            //   0f95c0               | lea                 ecx, [esp + 0xdc]
            //   20c8                 | cmp                 eax, 5

        $sequence_7 = { 660f7f8424f0010000 660f7f8424e0010000 660f7f8424d0010000 660f7f8424c0010000 660f7f8424b0010000 }
            // n = 5, score = 200
            //   660f7f8424f0010000     | movdqa    xmm3, xmmword ptr [esp]
            //   660f7f8424e0010000     | movdqa    xmmword ptr [esp + 0x20], xmm5
            //   660f7f8424d0010000     | pxor    xmm3, xmm5
            //   660f7f8424c0010000     | pxor    xmm0, xmm6
            //   660f7f8424b0010000     | movdqa    xmm5, xmm0

        $sequence_8 = { 7227 b903000000 81fa???????? 721a b904000000 81fa???????? 720d }
            // n = 7, score = 200
            //   7227                 | jb                  0xfa
            //   b903000000           | mov                 edi, dword ptr [esp + 0xc]
            //   81fa????????         |                     
            //   721a                 | lea                 ebx, [esp + 0xc]
            //   b904000000           | test                edi, edi
            //   81fa????????         |                     
            //   720d                 | je                  0xc7

        $sequence_9 = { 0fb61403 83f93f 7509 80fa01 }
            // n = 4, score = 200
            //   0fb61403             | mov                 ecx, dword ptr [edi + ecx*8]
            //   83f93f               | jbe                 0x653
            //   7509                 | inc                 ecx
            //   80fa01               | mov                 byte ptr [esp + 0x20], 1

    condition:
        7 of them and filesize < 8011776
}