rule win_dadstache_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.dadstache."
        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.dadstache"
        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 = { 8b45fc 05f4feffff 85c9 8945f4 }
            // n = 4, score = 500
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   05f4feffff           | add                 eax, 0xfffffef4
            //   85c9                 | test                ecx, ecx
            //   8945f4               | mov                 dword ptr [ebp - 0xc], eax

        $sequence_1 = { 5d c3 85c0 75be }
            // n = 4, score = 500
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   85c0                 | test                eax, eax
            //   75be                 | jne                 0xffffffc0

        $sequence_2 = { 51 8d4df8 51 6a1f 50 }
            // n = 5, score = 500
            //   51                   | push                ecx
            //   8d4df8               | lea                 ecx, [ebp - 8]
            //   51                   | push                ecx
            //   6a1f                 | push                0x1f
            //   50                   | push                eax

        $sequence_3 = { 0f47c1 50 8b4670 ffb010020000 ff36 ff15???????? }
            // n = 6, score = 500
            //   0f47c1               | cmova               eax, ecx
            //   50                   | push                eax
            //   8b4670               | mov                 eax, dword ptr [esi + 0x70]
            //   ffb010020000         | push                dword ptr [eax + 0x210]
            //   ff36                 | push                dword ptr [esi]
            //   ff15????????         |                     

        $sequence_4 = { 85db 0f858e000000 6aff ff35???????? ff15???????? 85c0 756c }
            // n = 7, score = 500
            //   85db                 | test                ebx, ebx
            //   0f858e000000         | jne                 0x94
            //   6aff                 | push                -1
            //   ff35????????         |                     
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   756c                 | jne                 0x6e

        $sequence_5 = { c1e108 8bf7 0bc8 c745d801000000 0fb64201 c1e108 }
            // n = 6, score = 500
            //   c1e108               | shl                 ecx, 8
            //   8bf7                 | mov                 esi, edi
            //   0bc8                 | or                  ecx, eax
            //   c745d801000000       | mov                 dword ptr [ebp - 0x28], 1
            //   0fb64201             | movzx               eax, byte ptr [edx + 1]
            //   c1e108               | shl                 ecx, 8

        $sequence_6 = { ff15???????? 68c8000000 ff15???????? 3bf7 0f826affffff eb0c ff35???????? }
            // n = 7, score = 500
            //   ff15????????         |                     
            //   68c8000000           | push                0xc8
            //   ff15????????         |                     
            //   3bf7                 | cmp                 esi, edi
            //   0f826affffff         | jb                  0xffffff70
            //   eb0c                 | jmp                 0xe
            //   ff35????????         |                     

        $sequence_7 = { 6888020000 e8???????? 8bf8 83c404 85ff 7505 }
            // n = 6, score = 500
            //   6888020000           | push                0x288
            //   e8????????           |                     
            //   8bf8                 | mov                 edi, eax
            //   83c404               | add                 esp, 4
            //   85ff                 | test                edi, edi
            //   7505                 | jne                 7

        $sequence_8 = { 8b06 85c0 75dc 8b7df4 83c714 897df4 }
            // n = 6, score = 200
            //   8b06                 | mov                 eax, dword ptr [esi]
            //   85c0                 | test                eax, eax
            //   75dc                 | jne                 0xffffffde
            //   8b7df4               | mov                 edi, dword ptr [ebp - 0xc]
            //   83c714               | add                 edi, 0x14
            //   897df4               | mov                 dword ptr [ebp - 0xc], edi

        $sequence_9 = { 3b7818 8b45fc 72bd 5f 5e 33c0 }
            // n = 6, score = 200
            //   3b7818               | cmp                 edi, dword ptr [eax + 0x18]
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   72bd                 | jb                  0xffffffbf
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   33c0                 | xor                 eax, eax

        $sequence_10 = { 03c0 35b70dc104 eb02 03c0 85c0 7909 03c0 }
            // n = 7, score = 200
            //   03c0                 | add                 eax, eax
            //   35b70dc104           | xor                 eax, 0x4c10db7
            //   eb02                 | jmp                 4
            //   03c0                 | add                 eax, eax
            //   85c0                 | test                eax, eax
            //   7909                 | jns                 0xb
            //   03c0                 | add                 eax, eax

        $sequence_11 = { 83fa08 0f8259010000 833d????????02 0f8c4c010000 }
            // n = 4, score = 200
            //   83fa08               | cmp                 edx, 8
            //   0f8259010000         | jb                  0x15f
            //   833d????????02       |                     
            //   0f8c4c010000         | jl                  0x152

        $sequence_12 = { 0f84e3000000 53 8b5904 895df0 8b5908 }
            // n = 5, score = 200
            //   0f84e3000000         | je                  0xe9
            //   53                   | push                ebx
            //   8b5904               | mov                 ebx, dword ptr [ecx + 4]
            //   895df0               | mov                 dword ptr [ebp - 0x10], ebx
            //   8b5908               | mov                 ebx, dword ptr [ecx + 8]

        $sequence_13 = { 4a 03d7 8d4fff 03ce 85ff 7436 }
            // n = 6, score = 200
            //   4a                   | dec                 edx
            //   03d7                 | add                 edx, edi
            //   8d4fff               | lea                 ecx, [edi - 1]
            //   03ce                 | add                 ecx, esi
            //   85ff                 | test                edi, edi
            //   7436                 | je                  0x38

        $sequence_14 = { 8d52ff 83ef01 75f0 5f 8bc6 }
            // n = 5, score = 200
            //   8d52ff               | lea                 edx, [edx - 1]
            //   83ef01               | sub                 edi, 1
            //   75f0                 | jne                 0xfffffff2
            //   5f                   | pop                 edi
            //   8bc6                 | mov                 eax, esi

        $sequence_15 = { 83c70c 3bf7 741e 660f1f840000000000 8b4e30 8d5580 }
            // n = 6, score = 200
            //   83c70c               | add                 edi, 0xc
            //   3bf7                 | cmp                 esi, edi
            //   741e                 | je                  0x20
            //   660f1f840000000000     | nop    word ptr [eax + eax]
            //   8b4e30               | mov                 ecx, dword ptr [esi + 0x30]
            //   8d5580               | lea                 edx, [ebp - 0x80]

    condition:
        7 of them and filesize < 580608
}

rule win_dadstache_w0 {
    meta:
        author =  "Elastic Security"
        description = "APT40 second stage implant"
        source = "https://www.elastic.co/blog/advanced-techniques-used-in-malaysian-focused-apt-campaign"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.dadstache"
        malpedia_version = "20200626"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $a = "/list_direction" fullword wide
        $b = "/post_document" fullword wide
        $c = "/postlogin" fullword wide
        $d = "Download Read Path Failed %s" fullword ascii
        $e = "Open Pipe Failed %s" fullword ascii
        $f = "Open Remote File %s Failed For: %s" fullword ascii
        $g = "Download Read Path Failed %s" fullword ascii
        $h = "\\cmd.exe" fullword wide
    condition:
        all of them
}