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 (20230125 | Detects win.breach_rat.)
rule win_breach_rat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        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 = "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 = { 8b17 eb02 8bd7 8b4f10 8bf8 03ca 8975f0 }
            // n = 7, score = 200
            //   8b17                 | mov                 edx, dword ptr [edi]
            //   eb02                 | jmp                 4
            //   8bd7                 | mov                 edx, edi
            //   8b4f10               | mov                 ecx, dword ptr [edi + 0x10]
            //   8bf8                 | mov                 edi, eax
            //   03ca                 | add                 ecx, edx
            //   8975f0               | mov                 dword ptr [ebp - 0x10], esi

        $sequence_1 = { 85c0 7422 8b4d0c c6450c00 ff750c c645fc00 8b09 }
            // n = 7, score = 200
            //   85c0                 | test                eax, eax
            //   7422                 | je                  0x24
            //   8b4d0c               | mov                 ecx, dword ptr [ebp + 0xc]
            //   c6450c00             | mov                 byte ptr [ebp + 0xc], 0
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   c645fc00             | mov                 byte ptr [ebp - 4], 0
            //   8b09                 | mov                 ecx, dword ptr [ecx]

        $sequence_2 = { 8bc8 e8???????? 8d8ddcf3ffff c745fcffffffff e8???????? 68???????? }
            // n = 6, score = 200
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   8d8ddcf3ffff         | lea                 ecx, [ebp - 0xc24]
            //   c745fcffffffff       | mov                 dword ptr [ebp - 4], 0xffffffff
            //   e8????????           |                     
            //   68????????           |                     

        $sequence_3 = { 6639859cfdffff 7418 8d859cfdffff 8d5002 668b08 83c002 6685c9 }
            // n = 7, score = 200
            //   6639859cfdffff       | cmp                 word ptr [ebp - 0x264], ax
            //   7418                 | je                  0x1a
            //   8d859cfdffff         | lea                 eax, [ebp - 0x264]
            //   8d5002               | lea                 edx, [eax + 2]
            //   668b08               | mov                 cx, word ptr [eax]
            //   83c002               | add                 eax, 2
            //   6685c9               | test                cx, cx

        $sequence_4 = { 837df010 720b ff75dc e8???????? 83c404 68???????? }
            // n = 6, score = 200
            //   837df010             | cmp                 dword ptr [ebp - 0x10], 0x10
            //   720b                 | jb                  0xd
            //   ff75dc               | push                dword ptr [ebp - 0x24]
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   68????????           |                     

        $sequence_5 = { c6459800 e8???????? 68???????? 6a01 8d4598 c745fc00000000 50 }
            // n = 7, score = 200
            //   c6459800             | mov                 byte ptr [ebp - 0x68], 0
            //   e8????????           |                     
            //   68????????           |                     
            //   6a01                 | push                1
            //   8d4598               | lea                 eax, [ebp - 0x68]
            //   c745fc00000000       | mov                 dword ptr [ebp - 4], 0
            //   50                   | push                eax

        $sequence_6 = { c1fa02 8bc2 895dd8 c1e81f 03c2 0f84620b0000 8b07 }
            // n = 7, score = 200
            //   c1fa02               | sar                 edx, 2
            //   8bc2                 | mov                 eax, edx
            //   895dd8               | mov                 dword ptr [ebp - 0x28], ebx
            //   c1e81f               | shr                 eax, 0x1f
            //   03c2                 | add                 eax, edx
            //   0f84620b0000         | je                  0xb68
            //   8b07                 | mov                 eax, dword ptr [edi]

        $sequence_7 = { e8???????? 68???????? 8d8d64f3ffff e8???????? c745fcdd000000 68???????? 8d8564f3ffff }
            // n = 7, score = 200
            //   e8????????           |                     
            //   68????????           |                     
            //   8d8d64f3ffff         | lea                 ecx, [ebp - 0xc9c]
            //   e8????????           |                     
            //   c745fcdd000000       | mov                 dword ptr [ebp - 4], 0xdd
            //   68????????           |                     
            //   8d8564f3ffff         | lea                 eax, [ebp - 0xc9c]

        $sequence_8 = { e8???????? 68???????? 8d85e4f1ffff c745fce5000000 50 8bce e8???????? }
            // n = 7, score = 200
            //   e8????????           |                     
            //   68????????           |                     
            //   8d85e4f1ffff         | lea                 eax, [ebp - 0xe1c]
            //   c745fce5000000       | mov                 dword ptr [ebp - 4], 0xe5
            //   50                   | push                eax
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     

        $sequence_9 = { 8bc8 e8???????? 8d8dccf7ffff c745fcffffffff e8???????? 68???????? 8d8d5cf2ffff }
            // n = 7, score = 200
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   8d8dccf7ffff         | lea                 ecx, [ebp - 0x834]
            //   c745fcffffffff       | mov                 dword ptr [ebp - 4], 0xffffffff
            //   e8????????           |                     
            //   68????????           |                     
            //   8d8d5cf2ffff         | lea                 ecx, [ebp - 0xda4]

    condition:
        7 of them and filesize < 645120
}
Download all Yara Rules