SYMBOLCOMMON_NAMEaka. SYNONYMS
win.breach_rat (Back to overview)

BreachRAT

Actor(s): Operation C-Major


This is a backdoor which FireEye call the Breach Remote Administration Tool (BreachRAT), written in C++. The malware name is derived from the hardcoded PDB path found in the RAT: C:\Work\Breach Remote Administration Tool\Release\Client.pdb

References
2016-06-03FireEyeYin Hong Chang, Sudeep Singh
@online{chang:20160603:sends:176f9ab, author = {Yin Hong Chang and Sudeep Singh}, title = {{APT Group Sends Spear Phishing Emails to Indian Government Officials}}, date = {2016-06-03}, organization = {FireEye}, url = {https://www.fireeye.com/blog/threat-research/2016/06/apt_group_sends_spea.html}, language = {English}, urldate = {2019-12-20} } APT Group Sends Spear Phishing Emails to Indian Government Officials
BreachRAT DarkComet Operation C-Major
Yara Rules
[TLP:WHITE] win_breach_rat_auto (20220411 | Detects win.breach_rat.)
rule win_breach_rat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.breach_rat."
        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.breach_rat"
        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 = { ebba 55 8bec 51 51 8d45f8 50 }
            // n = 7, score = 200
            //   ebba                 | jmp                 0xffffffbc
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   51                   | push                ecx
            //   51                   | push                ecx
            //   8d45f8               | lea                 eax, dword ptr [ebp - 8]
            //   50                   | push                eax

        $sequence_1 = { 8d85f8fdffff 56 6804010000 50 6a00 8bf1 ff15???????? }
            // n = 7, score = 200
            //   8d85f8fdffff         | lea                 eax, dword ptr [ebp - 0x208]
            //   56                   | push                esi
            //   6804010000           | push                0x104
            //   50                   | push                eax
            //   6a00                 | push                0
            //   8bf1                 | mov                 esi, ecx
            //   ff15????????         |                     

        $sequence_2 = { 83ec08 56 57 8bf9 c745f000000000 897dec c707???????? }
            // n = 7, score = 200
            //   83ec08               | sub                 esp, 8
            //   56                   | push                esi
            //   57                   | push                edi
            //   8bf9                 | mov                 edi, ecx
            //   c745f000000000       | mov                 dword ptr [ebp - 0x10], 0
            //   897dec               | mov                 dword ptr [ebp - 0x14], edi
            //   c707????????         |                     

        $sequence_3 = { 50 e8???????? c645fc02 837ddc10 720b ff75c8 e8???????? }
            // n = 7, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   c645fc02             | mov                 byte ptr [ebp - 4], 2
            //   837ddc10             | cmp                 dword ptr [ebp - 0x24], 0x10
            //   720b                 | jb                  0xd
            //   ff75c8               | push                dword ptr [ebp - 0x38]
            //   e8????????           |                     

        $sequence_4 = { c7458c00000000 c7459000000000 c7459400000000 8d5598 c645fc0a 8bcf e8???????? }
            // n = 7, score = 200
            //   c7458c00000000       | mov                 dword ptr [ebp - 0x74], 0
            //   c7459000000000       | mov                 dword ptr [ebp - 0x70], 0
            //   c7459400000000       | mov                 dword ptr [ebp - 0x6c], 0
            //   8d5598               | lea                 edx, dword ptr [ebp - 0x68]
            //   c645fc0a             | mov                 byte ptr [ebp - 4], 0xa
            //   8bcf                 | mov                 ecx, edi
            //   e8????????           |                     

        $sequence_5 = { 8d4601 50 e8???????? 83c404 8bf8 33d2 897de0 }
            // n = 7, score = 200
            //   8d4601               | lea                 eax, dword ptr [esi + 1]
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8bf8                 | mov                 edi, eax
            //   33d2                 | xor                 edx, edx
            //   897de0               | mov                 dword ptr [ebp - 0x20], edi

        $sequence_6 = { 8b45f8 884dcd 8b4dc0 d3ea 8b8c85f8feffff 2bf9 8b45cc }
            // n = 7, score = 200
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   884dcd               | mov                 byte ptr [ebp - 0x33], cl
            //   8b4dc0               | mov                 ecx, dword ptr [ebp - 0x40]
            //   d3ea                 | shr                 edx, cl
            //   8b8c85f8feffff       | mov                 ecx, dword ptr [ebp + eax*4 - 0x108]
            //   2bf9                 | sub                 edi, ecx
            //   8b45cc               | mov                 eax, dword ptr [ebp - 0x34]

        $sequence_7 = { 39442414 7520 85f6 0f8565ffffff 837c242820 7339 56 }
            // n = 7, score = 200
            //   39442414             | cmp                 dword ptr [esp + 0x14], eax
            //   7520                 | jne                 0x22
            //   85f6                 | test                esi, esi
            //   0f8565ffffff         | jne                 0xffffff6b
            //   837c242820           | cmp                 dword ptr [esp + 0x28], 0x20
            //   7339                 | jae                 0x3b
            //   56                   | push                esi

        $sequence_8 = { 50 8bce e8???????? 8bc8 e8???????? 8d8d14f2ffff c745fcffffffff }
            // n = 7, score = 200
            //   50                   | push                eax
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   8d8d14f2ffff         | lea                 ecx, dword ptr [ebp - 0xdec]
            //   c745fcffffffff       | mov                 dword ptr [ebp - 4], 0xffffffff

        $sequence_9 = { ff7640 6800400000 6a01 ff7644 e8???????? 83c410 894604 }
            // n = 7, score = 200
            //   ff7640               | push                dword ptr [esi + 0x40]
            //   6800400000           | push                0x4000
            //   6a01                 | push                1
            //   ff7644               | push                dword ptr [esi + 0x44]
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   894604               | mov                 dword ptr [esi + 4], eax

    condition:
        7 of them and filesize < 645120
}
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