rule win_dadstache_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-10-14"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.5.0"
        tool_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.dadstache"
        malpedia_rule_date = "20201014"
        malpedia_hash = "a7e3bd57eaf12bf3ea29a863c041091ba3af9ac9"
        malpedia_version = "20201014"
        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 = { 8bf1 8b4d0c 8b7b10 3bf9 0f82ae000000 }
            // n = 5, score = 500
            //   8bf1                 | mov                 esi, ecx
            //   8b4d0c               | mov                 ecx, dword ptr [ebp + 0xc]
            //   8b7b10               | mov                 edi, dword ptr [ebx + 0x10]
            //   3bf9                 | cmp                 edi, ecx
            //   0f82ae000000         | jb                  0xb4

        $sequence_1 = { 03c1 50 51 e8???????? 83c40c 897e10 837e1410 }
            // n = 7, score = 500
            //   03c1                 | add                 eax, ecx
            //   50                   | push                eax
            //   51                   | push                ecx
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   897e10               | mov                 dword ptr [esi + 0x10], edi
            //   837e1410             | cmp                 dword ptr [esi + 0x14], 0x10

        $sequence_2 = { 7545 8d040f 394610 0f829f000000 894610 }
            // n = 5, score = 500
            //   7545                 | jne                 0x47
            //   8d040f               | lea                 eax, [edi + ecx]
            //   394610               | cmp                 dword ptr [esi + 0x10], eax
            //   0f829f000000         | jb                  0xa5
            //   894610               | mov                 dword ptr [esi + 0x10], eax

        $sequence_3 = { 394610 0f829f000000 894610 837e1410 7218 8b16 }
            // n = 6, score = 500
            //   394610               | cmp                 dword ptr [esi + 0x10], eax
            //   0f829f000000         | jb                  0xa5
            //   894610               | mov                 dword ptr [esi + 0x10], eax
            //   837e1410             | cmp                 dword ptr [esi + 0x14], 0x10
            //   7218                 | jb                  0x1a
            //   8b16                 | mov                 edx, dword ptr [esi]

        $sequence_4 = { 51 57 8bce e8???????? 84c0 7446 837b1410 }
            // n = 7, score = 500
            //   51                   | push                ecx
            //   57                   | push                edi
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   84c0                 | test                al, al
            //   7446                 | je                  0x48
            //   837b1410             | cmp                 dword ptr [ebx + 0x14], 0x10

        $sequence_5 = { 3bf9 0f82ae000000 2bf9 397d10 0f427d10 3bf3 }
            // n = 6, score = 500
            //   3bf9                 | cmp                 edi, ecx
            //   0f82ae000000         | jb                  0xb4
            //   2bf9                 | sub                 edi, ecx
            //   397d10               | cmp                 dword ptr [ebp + 0x10], edi
            //   0f427d10             | cmovb               edi, dword ptr [ebp + 0x10]
            //   3bf3                 | cmp                 esi, ebx

        $sequence_6 = { 56 57 8bf1 8b4d0c 8b7b10 3bf9 0f82ae000000 }
            // n = 7, score = 500
            //   56                   | push                esi
            //   57                   | push                edi
            //   8bf1                 | mov                 esi, ecx
            //   8b4d0c               | mov                 ecx, dword ptr [ebp + 0xc]
            //   8b7b10               | mov                 edi, dword ptr [ebx + 0x10]
            //   3bf9                 | cmp                 edi, ecx
            //   0f82ae000000         | jb                  0xb4

        $sequence_7 = { 7545 8d040f 394610 0f829f000000 }
            // n = 4, score = 500
            //   7545                 | jne                 0x47
            //   8d040f               | lea                 eax, [edi + ecx]
            //   394610               | cmp                 dword ptr [esi + 0x10], eax
            //   0f829f000000         | jb                  0xa5

        $sequence_8 = { 3bf3 7545 8d040f 394610 0f829f000000 894610 }
            // n = 6, score = 500
            //   3bf3                 | cmp                 esi, ebx
            //   7545                 | jne                 0x47
            //   8d040f               | lea                 eax, [edi + ecx]
            //   394610               | cmp                 dword ptr [esi + 0x10], eax
            //   0f829f000000         | jb                  0xa5
            //   894610               | mov                 dword ptr [esi + 0x10], eax

        $sequence_9 = { 8d040f 394610 0f829f000000 894610 }
            // n = 4, score = 500
            //   8d040f               | lea                 eax, [edi + ecx]
            //   394610               | cmp                 dword ptr [esi + 0x10], eax
            //   0f829f000000         | jb                  0xa5
            //   894610               | mov                 dword ptr [esi + 0x10], eax

    condition:
        7 of them and filesize < 319552
}

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
}