YARA · Trellix Advanced Research Center
TRELLIX_ARC_Ransom_Babuk
Rule to detect Babuk Locker
- Author
- TS @ McAfee ATR
- Date
- 2021-01-19
- Modified
- 2021-02-24
- Score / Quality
- 75 / 70
What this rule detects
Rule to detect Babuk Locker
Associated malware family: Babuk.
It defines 6 patterns (1 text, 5 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule TRELLIX_ARC_Ransom_Babuk : RANSOM T1027 T1083 T1057 T1082 T1129 T1490 T1543_003 FILE
{
meta:
= "Rule to detect Babuk Locker"
= "TS @ McAfee ATR"
= "7c0a3b4e-90aa-5442-aa5e-1a7fcae9bec8"
= "2021-01-19"
= "2021-02-24"
= "https://github.com/advanced-threat-research/Yara-Rules/"
= "https://github.com/advanced-threat-research/Yara-Rules//blob/1919562a59f190bda60c982424f6a24c542ee3e0/ransomware/RANSOM_BabukLocker_Jan2021.yar#L1-L25"
= "https://github.com/advanced-threat-research/Yara-Rules//blob/1919562a59f190bda60c982424f6a24c542ee3e0/LICENSE"
= "e10713a4a5f635767dcd54d609bed977"
= "123cebd1c2e66f3e91ee235cb9288df63dfaeba02e6df45f896cb50f38851a8f"
= 75
= 70
= "RANSOM, T1027, T1083, T1057, T1082, T1129, T1490, T1543.003, FILE"
= "v2"
= "Ransom:Win/Babuk"
= "Ransom"
= "T1027, T1083, T1057, T1082, T1129, T1490, T1543.003"
strings:
$s1 = {005C0048006F007700200054006F00200052006500730074006F0072006500200059006F00750072002000460069006C00650073002E007400780074}
$s2 = "delete shadows /all /quiet" fullword wide
$pattern1 = {006D656D74617300006D65706F63730000736F70686F730000766565616D0000006261636B7570000047785673730000004778426C7200000047784657440000004778435644000000477843494D67720044656657617463680000000063634576744D67720000000063635365744D677200000000536176526F616D005254567363616E0051424643536572766963650051424944505365727669636500000000496E747569742E517569636B426F6F6B732E46435300}
$pattern2 = {004163725363683253766300004163726F6E69734167656E74000000004341534144324457656253766300000043414152435570646174655376630000730071}
$pattern3 = {FFB0154000C78584FDFFFFB8154000C78588FDFFFFC0154000C7858CFDFFFFC8154000C78590FDFFFFD0154000C78594FDFFFFD8154000C78598FDFFFFE0154000C7859CFDFFFFE8154000C785A0FDFFFFF0154000C785A4FDFFFFF8154000C785A8FDFFFF00164000C785ACFDFFFF08164000C785B0FDFFFF10164000C785B4FDFFFF18164000C785B8FDFFFF20164000C785BCFDFFFF28164000C785C0FDFFFF30164000C785C4FDFFFF38164000C785C8FDFFFF40164000C785CCFDFFFF48164000C785D0FDFFFF50164000C785D4FDFFFF581640}
$pattern4 = {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}
condition:
filesize >= 15KB and filesize <= 90KB and 1 of ( $s* ) and 3 of ( $pattern* )
}
Strings (6 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $s1 | hex | {005C0048006F007700200054006F00200052006500730074006F0072006500200059006F00750072002000460069006C00650073002E007400780074} | |
| $s2 | text | "delete shadows /all /quiet" | fullword wide |
| $pattern1 | hex | {006D656D74617300006D65706F63730000736F70686F730000766565616D0000006261636B7570000047785673730000004778426C7200000047784657440000004778435644000000477843494D677 … | |
| $pattern2 | hex | {004163725363683253766300004163726F6E69734167656E74000000004341534144324457656253766300000043414152435570646174655376630000730071} | |
| $pattern3 | hex | {FFB0154000C78584FDFFFFB8154000C78588FDFFFFC0154000C7858CFDFFFFC8154000C78590FDFFFFD0154000C78594FDFFFFD8154000C78598FDFFFFE0154000C7859CFDFFFFE8154000C785A0FDF … | |
| $pattern4 | hex | {400010104000181040002010400028104000301040003810400040104000481040005010400058104000601040006C10400078104000841040008C10400094104000A0104000B0104000C8104000DC1 … |
Condition
filesize >= 15KB and filesize <= 90KB and 1 of ( $s* ) and 3 of ( $pattern* )In plain words (Heuristic)
- The file must be smaller than 90KB (a cheap guard that skips large files).
- The file must be larger than 15KB.
- At least 1 patterns in ( $s* ) must match.
- At least 3 patterns in ( $pattern* ) 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).
- e10713a4a5f635767dcd54d609bed977
Licence & attribution
Author: TS @ McAfee ATR
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: 7c0a3b4e-90aa-5442-aa5e-1a7fcae9bec8
Metadata
| rule_version | v2 |
|---|---|
| malware_family | Ransom:Win/Babuk |
| malware_type | Ransom |
| mitre_attack | T1027, T1083, T1057, T1082, T1129, T1490, T1543.003 |
Tags:RANSOMT1027T1083T1057T1082T1129T1490T1543_003FILE
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