rule win_milkmaid_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.milkmaid."
        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.milkmaid"
        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 = { 8a5c2918 895c2428 7513 8b5508 }
            // n = 4, score = 100
            //   8a5c2918             | mov                 bl, byte ptr [ecx + ebp + 0x18]
            //   895c2428             | mov                 dword ptr [esp + 0x28], ebx
            //   7513                 | jne                 0x15
            //   8b5508               | mov                 edx, dword ptr [ebp + 8]

        $sequence_1 = { 8d4c2408 c744241801000000 e8???????? 50 6a00 6a00 }
            // n = 6, score = 100
            //   8d4c2408             | lea                 ecx, [esp + 8]
            //   c744241801000000     | mov                 dword ptr [esp + 0x18], 1
            //   e8????????           |                     
            //   50                   | push                eax
            //   6a00                 | push                0
            //   6a00                 | push                0

        $sequence_2 = { c68424dc28010002 e8???????? 8d4c2410 c68424dc28010001 e8???????? 8d4c2414 889c24dc280100 }
            // n = 7, score = 100
            //   c68424dc28010002     | mov                 byte ptr [esp + 0x128dc], 2
            //   e8????????           |                     
            //   8d4c2410             | lea                 ecx, [esp + 0x10]
            //   c68424dc28010001     | mov                 byte ptr [esp + 0x128dc], 1
            //   e8????????           |                     
            //   8d4c2414             | lea                 ecx, [esp + 0x14]
            //   889c24dc280100       | mov                 byte ptr [esp + 0x128dc], bl

        $sequence_3 = { 53 89542448 53 53 8d4c2434 }
            // n = 5, score = 100
            //   53                   | push                ebx
            //   89542448             | mov                 dword ptr [esp + 0x48], edx
            //   53                   | push                ebx
            //   53                   | push                ebx
            //   8d4c2434             | lea                 ecx, [esp + 0x34]

        $sequence_4 = { c3 57 56 8d4c241c e8???????? 8d4c2414 }
            // n = 6, score = 100
            //   c3                   | ret                 
            //   57                   | push                edi
            //   56                   | push                esi
            //   8d4c241c             | lea                 ecx, [esp + 0x1c]
            //   e8????????           |                     
            //   8d4c2414             | lea                 ecx, [esp + 0x14]

        $sequence_5 = { 8b8c24d4280100 5f 5e 5b 64890d00000000 }
            // n = 5, score = 100
            //   8b8c24d4280100       | mov                 ecx, dword ptr [esp + 0x128d4]
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx
            //   64890d00000000       | mov                 dword ptr fs:[0], ecx

        $sequence_6 = { 2bd1 8b5c2428 8b6c242c 8d4c0201 }
            // n = 4, score = 100
            //   2bd1                 | sub                 edx, ecx
            //   8b5c2428             | mov                 ebx, dword ptr [esp + 0x28]
            //   8b6c242c             | mov                 ebp, dword ptr [esp + 0x2c]
            //   8d4c0201             | lea                 ecx, [edx + eax + 1]

        $sequence_7 = { 7440 56 ff15???????? 8d4c2414 e8???????? }
            // n = 5, score = 100
            //   7440                 | je                  0x42
            //   56                   | push                esi
            //   ff15????????         |                     
            //   8d4c2414             | lea                 ecx, [esp + 0x14]
            //   e8????????           |                     

    condition:
        7 of them and filesize < 65536
}