rule win_cerber_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-03-28"
        version = "1"
        description = "Detects win.cerber."
        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.cerber"
        malpedia_rule_date = "20230328"
        malpedia_hash = "9d2d75cef573c1c2d861f5197df8f563b05a305d"
        malpedia_version = "20230407"
        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 = { 837d1000 6a20 8db41848020000 59 f3a5 }
            // n = 5, score = 1200
            //   837d1000             | cmp                 dword ptr [ebp + 0x10], 0
            //   6a20                 | push                0x20
            //   8db41848020000       | lea                 esi, [eax + ebx + 0x248]
            //   59                   | pop                 ecx
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]

        $sequence_1 = { 6a20 5b 3bcb 725c 8bc1 }
            // n = 5, score = 1200
            //   6a20                 | push                0x20
            //   5b                   | pop                 ebx
            //   3bcb                 | cmp                 ecx, ebx
            //   725c                 | jb                  0x5e
            //   8bc1                 | mov                 eax, ecx

        $sequence_2 = { 7424 8bf9 2bfa 8d3cbe 49 83ef04 897d10 }
            // n = 7, score = 1200
            //   7424                 | je                  0x26
            //   8bf9                 | mov                 edi, ecx
            //   2bfa                 | sub                 edi, edx
            //   8d3cbe               | lea                 edi, [esi + edi*4]
            //   49                   | dec                 ecx
            //   83ef04               | sub                 edi, 4
            //   897d10               | mov                 dword ptr [ebp + 0x10], edi

        $sequence_3 = { 41 894df8 83f920 72f0 d3650c }
            // n = 5, score = 1200
            //   41                   | inc                 ecx
            //   894df8               | mov                 dword ptr [ebp - 8], ecx
            //   83f920               | cmp                 ecx, 0x20
            //   72f0                 | jb                  0xfffffff2
            //   d3650c               | shl                 dword ptr [ebp + 0xc], cl

        $sequence_4 = { 41 894df0 bb80000000 85ff 7e1a 895dfc 297dfc }
            // n = 7, score = 1200
            //   41                   | inc                 ecx
            //   894df0               | mov                 dword ptr [ebp - 0x10], ecx
            //   bb80000000           | mov                 ebx, 0x80
            //   85ff                 | test                edi, edi
            //   7e1a                 | jle                 0x1c
            //   895dfc               | mov                 dword ptr [ebp - 4], ebx
            //   297dfc               | sub                 dword ptr [ebp - 4], edi

        $sequence_5 = { 837d0c00 7507 6a0d e9???????? ff7528 8d8534fdffff 53 }
            // n = 7, score = 1200
            //   837d0c00             | cmp                 dword ptr [ebp + 0xc], 0
            //   7507                 | jne                 9
            //   6a0d                 | push                0xd
            //   e9????????           |                     
            //   ff7528               | push                dword ptr [ebp + 0x28]
            //   8d8534fdffff         | lea                 eax, [ebp - 0x2cc]
            //   53                   | push                ebx

        $sequence_6 = { 7422 83f801 750b 4a b800000080 83e904 }
            // n = 6, score = 1200
            //   7422                 | je                  0x24
            //   83f801               | cmp                 eax, 1
            //   750b                 | jne                 0xd
            //   4a                   | dec                 edx
            //   b800000080           | mov                 eax, 0x80000000
            //   83e904               | sub                 ecx, 4

        $sequence_7 = { 7425 ff7528 53 ff7520 }
            // n = 4, score = 1200
            //   7425                 | je                  0x27
            //   ff7528               | push                dword ptr [ebp + 0x28]
            //   53                   | push                ebx
            //   ff7520               | push                dword ptr [ebp + 0x20]

    condition:
        7 of them and filesize < 573440
}