rule win_bs2005_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.bs2005."
        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.bs2005"
        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 = { 885403ff 83f820 7ce0 8bd0 c6041300 }
            // n = 5, score = 100
            //   885403ff             | mov                 byte ptr [ebx + eax - 1], dl
            //   83f820               | cmp                 eax, 0x20
            //   7ce0                 | jl                  0xffffffe2
            //   8bd0                 | mov                 edx, eax
            //   c6041300             | mov                 byte ptr [ebx + edx], 0

        $sequence_1 = { e8???????? 689c000000 8d8dd8fcffff 6a00 51 e8???????? 8b35???????? }
            // n = 7, score = 100
            //   e8????????           |                     
            //   689c000000           | push                0x9c
            //   8d8dd8fcffff         | lea                 ecx, dword ptr [ebp - 0x328]
            //   6a00                 | push                0
            //   51                   | push                ecx
            //   e8????????           |                     
            //   8b35????????         |                     

        $sequence_2 = { 8d8578fdffff 8d9b00000000 c60000 40 }
            // n = 4, score = 100
            //   8d8578fdffff         | lea                 eax, dword ptr [ebp - 0x288]
            //   8d9b00000000         | lea                 ebx, dword ptr [ebx]
            //   c60000               | mov                 byte ptr [eax], 0
            //   40                   | inc                 eax

        $sequence_3 = { 75f9 8b874c060000 8b08 81c154010400 8bc1 8d7001 8d4900 }
            // n = 7, score = 100
            //   75f9                 | jne                 0xfffffffb
            //   8b874c060000         | mov                 eax, dword ptr [edi + 0x64c]
            //   8b08                 | mov                 ecx, dword ptr [eax]
            //   81c154010400         | add                 ecx, 0x40154
            //   8bc1                 | mov                 eax, ecx
            //   8d7001               | lea                 esi, dword ptr [eax + 1]
            //   8d4900               | lea                 ecx, dword ptr [ecx]

        $sequence_4 = { 50 ffd7 be40420f00 8da42400000000 8d8dd0feffff 51 }
            // n = 6, score = 100
            //   50                   | push                eax
            //   ffd7                 | call                edi
            //   be40420f00           | mov                 esi, 0xf4240
            //   8da42400000000       | lea                 esp, dword ptr [esp]
            //   8d8dd0feffff         | lea                 ecx, dword ptr [ebp - 0x130]
            //   51                   | push                ecx

        $sequence_5 = { eb09 3c2f 7505 b93f000000 8d5abf 83c8ff 80fb19 }
            // n = 7, score = 100
            //   eb09                 | jmp                 0xb
            //   3c2f                 | cmp                 al, 0x2f
            //   7505                 | jne                 7
            //   b93f000000           | mov                 ecx, 0x3f
            //   8d5abf               | lea                 ebx, dword ptr [edx - 0x41]
            //   83c8ff               | or                  eax, 0xffffffff
            //   80fb19               | cmp                 bl, 0x19

        $sequence_6 = { 85c9 7e1d 8b95e0feffff 51 52 8d85e4feffff 50 }
            // n = 7, score = 100
            //   85c9                 | test                ecx, ecx
            //   7e1d                 | jle                 0x1f
            //   8b95e0feffff         | mov                 edx, dword ptr [ebp - 0x120]
            //   51                   | push                ecx
            //   52                   | push                edx
            //   8d85e4feffff         | lea                 eax, dword ptr [ebp - 0x11c]
            //   50                   | push                eax

        $sequence_7 = { 8b85a8feffff 3bc3 7403 50 ffd6 399dacfeffff 7409 }
            // n = 7, score = 100
            //   8b85a8feffff         | mov                 eax, dword ptr [ebp - 0x158]
            //   3bc3                 | cmp                 eax, ebx
            //   7403                 | je                  5
            //   50                   | push                eax
            //   ffd6                 | call                esi
            //   399dacfeffff         | cmp                 dword ptr [ebp - 0x154], ebx
            //   7409                 | je                  0xb

        $sequence_8 = { 56 50 8b412c ffd0 56 8b35???????? ffd6 }
            // n = 7, score = 100
            //   56                   | push                esi
            //   50                   | push                eax
            //   8b412c               | mov                 eax, dword ptr [ecx + 0x2c]
            //   ffd0                 | call                eax
            //   56                   | push                esi
            //   8b35????????         |                     
            //   ffd6                 | call                esi

        $sequence_9 = { c785b4feffff0c000000 c785bcfeffff01000000 899db8feffff ffd7 85c0 }
            // n = 5, score = 100
            //   c785b4feffff0c000000     | mov    dword ptr [ebp - 0x14c], 0xc
            //   c785bcfeffff01000000     | mov    dword ptr [ebp - 0x144], 1
            //   899db8feffff         | mov                 dword ptr [ebp - 0x148], ebx
            //   ffd7                 | call                edi
            //   85c0                 | test                eax, 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"
        hash = "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
}