YARA · Trellix Advanced Research Center
TRELLIX_ARC_Pwnlnx_Backdoor_Variant_6
Rule to detect the backdoor pwnlnx variant 6
- Author
- Marc Rivero | McAfee ATR Team
- Date
- 2020-04-17
- Modified
- 2020-08-14
- Score / Quality
- 75 / 70
What this rule detects
Rule to detect the backdoor pwnlnx variant 6
Associated malware family: Pwnlnx.
It defines 1 patterns (0 text, 1 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule TRELLIX_ARC_Pwnlnx_Backdoor_Variant_6 : BACKDOOR FILE
{
meta:
= "Rule to detect the backdoor pwnlnx variant 6"
= "Marc Rivero | McAfee ATR Team"
= "56bfe9c7-4cd4-51f6-a469-da8af52d64c2"
= "2020-04-17"
= "2020-08-14"
= "https://www.blackberry.com/content/dam/blackberry-com/asset/enterprise/pdf/direct/report-bb-decade-of-the-rats.pdf"
= "https://github.com/advanced-threat-research/Yara-Rules//blob/1919562a59f190bda60c982424f6a24c542ee3e0/APT/APT_decade_of_RATs.yar#L131-L161"
= "https://github.com/advanced-threat-research/Yara-Rules//blob/1919562a59f190bda60c982424f6a24c542ee3e0/LICENSE"
= "d29254ab907c9ef54349de3ec0dd8b22b4692c58ed7a7b340afbc6e44363f96a"
= "29423135a46ee7b9aa1bd8f1e6f7ffad09725787ad6e75312e1d34b18e3917d4"
= 75
= 70
= "BACKDOOR, FILE"
= "v1"
= "backdoor"
= "Backdoor:W32/Pwnlnx"
= "Cybercrime"
= "Unknown"
strings:
$bp = { 7F??4C4602??01??000000000000000001??3E????000000000000000000000000000000000000??????09??00000000000000004000000000??????2B??28??04??000014??000003??0000474E55????4D9585????AB6522????52AD3B??EC9B4BE8????????0000000000000000????00000000554889??????????4889??41544989??534889??488B??????????E8????????4C89??4889??48C7??????????FF??????????488B??????????89??E8????????89??5B415C5DC30F1F??E8????????554889??????????4889??41544989??534889??488B??????????E8????????4C89??4889??48C7??????????FF??????????488B??????????89??E8????????89??5B415C5DC30F1F??E8????????554889??415541544989??534889??4883????488B??????????65??8B????????????4889????31??E8????????4889??4C89??FF??????????488B??????????4189??E8????????488B??????????483D????????488D????75??EB??0F1F??????488B????4881??????????488D????74??0FB7??488D????48C7??????????31??E8????????498B????498B??????488D????488D????????????BA????????E8????????4885??74??4981??????????????488B????65??33????????????4489??75??4883????5B415C415D5DC3E8????????0F1F??E8????????554889??415541544989??534889??4883????488B??????????65??8B????????????4889????31??E8????????4889??4C89??FF??????????488B??????????4189??E8????????488B??????????483D????????488D????75??EB??0F1F??????488B????4881??????????488D????74??0FB7??488D????48C7??????????31??E8????????498B????498B??????488D????488D????????????BA????????E8????????4885??74??4981??????????????488B????65??33????????????4489??75??4883????5B415C415D5DC3E8????????0F1F??E8????????554889??415541544989??534889??4883????488B??????????65??8B????????????4889????31??E8????????4889??4C89??FF??????????488B??????????4189??E8????????488B??????????483D????????488D????75??EB??0F1F??????488B????4881??????????488D????74??0FB7??488D????48C7??????????31??E8????????498B????498B??????488D????488D????????????BA????????E8????????4885??74??4981??????????????488B????65??33????????????4489??75??4883????5B415C415D5DC3E8????????0F1F??E8????????554889??415541544989??534889??4883????488B??????????65??8B????????????4889????31??E8????????4889??4C89??FF??????????488B??????????4189??E8????????488B??????????483D????????488D????75??EB??0F1F??????488B????4881??????????488D????74??0FB7??488D????48C7??????????31??E8????????498B????498B??????488D????488D????????????BA????????E8????????4885??74??4981??????????????488B????65??33????????????4489??75??4883????5B415C415D5DC3E8????????0F1F??E8????????554889??41574589??415641554189??4154534889??4883????488B??????????4889????4889????4C89????483D????????4C8D????74??4C63??EB??0F1F??????498B????483D????????4C8D????74??498B??4C89??4889??E8????????85??75??4883????5B415C415D415E415F5DC30F1F??????????4589??4C8B????488B????4489??4889??488B????FF??????????4883????5B415C415D415E415F5DC3660F1F??????E8????????554889??41574589??41564D89??41554989??41544189??BA????????534889??488D????4883????4889????4889??65??8B????????????4889????31??E8????????488B??????????4881??????????488D????74??0FB7????4839??75??EB??0F1F????????????410FB7????4839??74??4C8B????4981??????????498D????75??4589??4D89??4C89??4489??4889??488B????FF??????????488B????65??33????????????75??4883????5B415C415D415E415F5DC3660F1F??????31??EB??E8????????0F1F??????662E0F1F????????????E8????????55BF????????4889??4881??????????65??8B????????????4889????31??488D??????????FF????????????B9????????4889??488D??????????F3??A5488D??????????48C7??????????BE????????B1??E8????????4885??74??48BA???????? }
condition:
uint16( 0 ) == 0x457f and filesize < 700KB and all of them
}
Strings (1 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $bp | hex | { 7F??4C4602??01??000000000000000001??3E????000000000000000000000000000000000000??????09??00000000000000004000000000??????2B??28??04??000014??000003??0000474E55 … |
Condition
uint16( 0 ) == 0x457f and filesize < 700KB and all of themIn plain words (Heuristic)
- The file must be smaller than 700KB (a cheap guard that skips large files).
- All patterns in the rule must match.
Test this rule in your browser
Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.
Sample hashes
Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).
- d29254ab907c9ef54349de3ec0dd8b22b4692c58ed7a7b340afbc6e44363f96a
Licence & attribution
Author: Marc Rivero | McAfee ATR Team
Source repository: Trellix Advanced Research Center @ 1919562a59
Licence: Apache License 2.0 (repository licence)
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: 56bfe9c7-4cd4-51f6-a469-da8af52d64c2
Metadata
| rule_version | v1 |
|---|---|
| malware_type | backdoor |
| malware_family | Backdoor:W32/Pwnlnx |
| actor_type | Cybercrime |
| actor_group | Unknown |
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