rule win_bs2005_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.bs2005"
        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 = { 8bf0 33c0 8945f0 85c9 7413 8b11 8d45f0 }
            // n = 7, score = 100
            //   8bf0                 | mov                 esi, eax
            //   33c0                 | xor                 eax, eax
            //   8945f0               | mov                 dword ptr [ebp - 0x10], eax
            //   85c9                 | test                ecx, ecx
            //   7413                 | je                  0x15
            //   8b11                 | mov                 edx, dword ptr [ecx]
            //   8d45f0               | lea                 eax, [ebp - 0x10]

        $sequence_1 = { 50 c745cca0fd4000 e8???????? 8b7508 bf63736de0 393e 0f85a5010000 }
            // n = 7, score = 100
            //   50                   | push                eax
            //   c745cca0fd4000       | mov                 dword ptr [ebp - 0x34], 0x40fda0
            //   e8????????           |                     
            //   8b7508               | mov                 esi, dword ptr [ebp + 8]
            //   bf63736de0           | mov                 edi, 0xe06d7363
            //   393e                 | cmp                 dword ptr [esi], edi
            //   0f85a5010000         | jne                 0x1ab

        $sequence_2 = { 6a04 8d4de0 51 6a03 6a00 68???????? 52 }
            // n = 7, score = 100
            //   6a04                 | push                4
            //   8d4de0               | lea                 ecx, [ebp - 0x20]
            //   51                   | push                ecx
            //   6a03                 | push                3
            //   6a00                 | push                0
            //   68????????           |                     
            //   52                   | push                edx

        $sequence_3 = { 83ceff 80f919 7708 0fbef2 83ee41 eb35 }
            // n = 6, score = 100
            //   83ceff               | or                  esi, 0xffffffff
            //   80f919               | cmp                 cl, 0x19
            //   7708                 | ja                  0xa
            //   0fbef2               | movsx               esi, dl
            //   83ee41               | sub                 esi, 0x41
            //   eb35                 | jmp                 0x37

        $sequence_4 = { 40 3bc6 7cf1 56 }
            // n = 4, score = 100
            //   40                   | inc                 eax
            //   3bc6                 | cmp                 eax, esi
            //   7cf1                 | jl                  0xfffffff3
            //   56                   | push                esi

        $sequence_5 = { 8d55f4 52 8d9e0c010800 53 50 8d860c010400 50 }
            // n = 7, score = 100
            //   8d55f4               | lea                 edx, [ebp - 0xc]
            //   52                   | push                edx
            //   8d9e0c010800         | lea                 ebx, [esi + 0x8010c]
            //   53                   | push                ebx
            //   50                   | push                eax
            //   8d860c010400         | lea                 eax, [esi + 0x4010c]
            //   50                   | push                eax

        $sequence_6 = { c785d8fcffff9c000000 ffd6 85c0 751b 8d85d8fcffff 50 }
            // n = 6, score = 100
            //   c785d8fcffff9c000000     | mov    dword ptr [ebp - 0x328], 0x9c
            //   ffd6                 | call                esi
            //   85c0                 | test                eax, eax
            //   751b                 | jne                 0x1d
            //   8d85d8fcffff         | lea                 eax, [ebp - 0x328]
            //   50                   | push                eax

        $sequence_7 = { 8b4dcc 8d45c8 50 83c610 }
            // n = 4, score = 100
            //   8b4dcc               | mov                 ecx, dword ptr [ebp - 0x34]
            //   8d45c8               | lea                 eax, [ebp - 0x38]
            //   50                   | push                eax
            //   83c610               | add                 esi, 0x10

        $sequence_8 = { 6801000080 ff15???????? 85c0 7533 8b4de8 6a04 8945e0 }
            // n = 7, score = 100
            //   6801000080           | push                0x80000001
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7533                 | jne                 0x35
            //   8b4de8               | mov                 ecx, dword ptr [ebp - 0x18]
            //   6a04                 | push                4
            //   8945e0               | mov                 dword ptr [ebp - 0x20], eax

        $sequence_9 = { 2bc6 40 50 8b02 51 056c030400 50 }
            // n = 7, score = 100
            //   2bc6                 | sub                 eax, esi
            //   40                   | inc                 eax
            //   50                   | push                eax
            //   8b02                 | mov                 eax, dword ptr [edx]
            //   51                   | push                ecx
            //   056c030400           | add                 eax, 0x4036c
            //   50                   | push                eax

    condition:
        7 of them and filesize < 212992
}

import "pe"

rule win_bs2005_w0 {
    meta:
        description = "Detects malware from APT 15 report by NCC Group"
        author = "Florian Roth"
        reference = "https://goo.gl/HZ5XMN"
        date = "2018-03-10"
        hash1 = "750d9eecd533f89b8aa13aeab173a1cf813b021b6824bc30e60f5db6fa7b950b"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.bs2005"
        malpedia_version = "20180312"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $x1 = "AAAAKQAASCMAABi+AABnhEBj8vep7VRoAEPRWLweGc0/eiDrXGajJXRxbXsTXAcZAABK4QAAPWwAACzWAAByrg==" fullword ascii
        $x2 = "AAAAKQAASCMAABi+AABnhKv3kXJJousn5YzkjGF46eE3G8ZGse4B9uoqJo8Q2oF0AABK4QAAPWwAACzWAAByrg==" fullword ascii

        $a1 = "http://%s/content.html?id=%s" fullword ascii
        $a2 = "http://%s/main.php?ssid=%s" fullword ascii
        $a3 = "http://%s/webmail.php?id=%s" fullword ascii
        $a9 = "http://%s/error.html?tab=%s" fullword ascii

        $s1 = "%s\\~tmp.txt" fullword ascii
        $s2 = "%s /C %s >>\"%s\" 2>&1" fullword ascii
        $s3 = "DisableFirstRunCustomize" fullword ascii
    condition:
        1 of ($x*) or 2 of them
}