rule win_biscuit_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.biscuit."
        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.biscuit"
        malpedia_rule_date = "20220405"
        malpedia_hash = "ecd38294bd47d5589be5cd5490dc8bb4804afc2a"
        malpedia_version = "20220411"
        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 = { 6800020000 6a00 ff15???????? 8b4304 8d942424020000 }
            // n = 5, score = 100
            //   6800020000           | push                0x200
            //   6a00                 | push                0
            //   ff15????????         |                     
            //   8b4304               | mov                 eax, dword ptr [ebx + 4]
            //   8d942424020000       | lea                 edx, dword ptr [esp + 0x224]

        $sequence_1 = { e8???????? 8bfd 83c9ff 33c0 83c410 f2ae f7d1 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   8bfd                 | mov                 edi, ebp
            //   83c9ff               | or                  ecx, 0xffffffff
            //   33c0                 | xor                 eax, eax
            //   83c410               | add                 esp, 0x10
            //   f2ae                 | repne scasb         al, byte ptr es:[edi]
            //   f7d1                 | not                 ecx

        $sequence_2 = { eb22 8b85dcbfffff 83e801 8985749fffff 8b8d749fffff 8a11 80ea01 }
            // n = 7, score = 100
            //   eb22                 | jmp                 0x24
            //   8b85dcbfffff         | mov                 eax, dword ptr [ebp - 0x4024]
            //   83e801               | sub                 eax, 1
            //   8985749fffff         | mov                 dword ptr [ebp - 0x608c], eax
            //   8b8d749fffff         | mov                 ecx, dword ptr [ebp - 0x608c]
            //   8a11                 | mov                 dl, byte ptr [ecx]
            //   80ea01               | sub                 dl, 1

        $sequence_3 = { 81faff000000 752f 8b85e4bfffff 83c002 8985ac9fffff 8b8ddcbfffff 83e901 }
            // n = 7, score = 100
            //   81faff000000         | cmp                 edx, 0xff
            //   752f                 | jne                 0x31
            //   8b85e4bfffff         | mov                 eax, dword ptr [ebp - 0x401c]
            //   83c002               | add                 eax, 2
            //   8985ac9fffff         | mov                 dword ptr [ebp - 0x6054], eax
            //   8b8ddcbfffff         | mov                 ecx, dword ptr [ebp - 0x4024]
            //   83e901               | sub                 ecx, 1

        $sequence_4 = { 8b9550b7ffff 52 e8???????? 83c404 eb22 8b85e8faffff 83e801 }
            // n = 7, score = 100
            //   8b9550b7ffff         | mov                 edx, dword ptr [ebp - 0x48b0]
            //   52                   | push                edx
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   eb22                 | jmp                 0x24
            //   8b85e8faffff         | mov                 eax, dword ptr [ebp - 0x518]
            //   83e801               | sub                 eax, 1

        $sequence_5 = { f2ae 8bca 4f c1e902 f3a5 8bca 8d442458 }
            // n = 7, score = 100
            //   f2ae                 | repne scasb         al, byte ptr es:[edi]
            //   8bca                 | mov                 ecx, edx
            //   4f                   | dec                 edi
            //   c1e902               | shr                 ecx, 2
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   8bca                 | mov                 ecx, edx
            //   8d442458             | lea                 eax, dword ptr [esp + 0x58]

        $sequence_6 = { e9???????? 8d8500b9ffff 50 b9???????? e8???????? 898524b8ffff }
            // n = 6, score = 100
            //   e9????????           |                     
            //   8d8500b9ffff         | lea                 eax, dword ptr [ebp - 0x4700]
            //   50                   | push                eax
            //   b9????????           |                     
            //   e8????????           |                     
            //   898524b8ffff         | mov                 dword ptr [ebp - 0x47dc], eax

        $sequence_7 = { 0fbe0d???????? 51 8b958c9fffff 52 e8???????? 83c40c }
            // n = 6, score = 100
            //   0fbe0d????????       |                     
            //   51                   | push                ecx
            //   8b958c9fffff         | mov                 edx, dword ptr [ebp - 0x6074]
            //   52                   | push                edx
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc

        $sequence_8 = { e8???????? e9???????? b911000000 33c0 8dbd34daffff f3ab }
            // n = 6, score = 100
            //   e8????????           |                     
            //   e9????????           |                     
            //   b911000000           | mov                 ecx, 0x11
            //   33c0                 | xor                 eax, eax
            //   8dbd34daffff         | lea                 edi, dword ptr [ebp - 0x25cc]
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax

        $sequence_9 = { 8b85e8faffff 83e801 898580b6ffff 8b8d80b6ffff 8a11 80ea01 }
            // n = 6, score = 100
            //   8b85e8faffff         | mov                 eax, dword ptr [ebp - 0x518]
            //   83e801               | sub                 eax, 1
            //   898580b6ffff         | mov                 dword ptr [ebp - 0x4980], eax
            //   8b8d80b6ffff         | mov                 ecx, dword ptr [ebp - 0x4980]
            //   8a11                 | mov                 dl, byte ptr [ecx]
            //   80ea01               | sub                 dl, 1

    condition:
        7 of them and filesize < 180224
}