Potential Suspicious Registry File Imported Via Reg.EXE

Severity: medium
Author: frack113, Nasreddine Bencherchali
Source: upstream

Detects the import of '.reg' files from suspicious paths using the 'reg.exe' utility

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1112` Modify Registry
Defense Evasion	`T1112` Modify Registry

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_img`

or:
Image|endswith: '\reg.exe'
OriginalFileName: reg.exe

Stage 2: `all of selection_cli`

CommandLine|contains: ' import '

Stage 3: `all of selection_paths`

or:
CommandLine|contains: '%appdata%'
CommandLine|contains: '%temp%'
CommandLine|contains: '%tmp%'
CommandLine|contains: 'C:\ProgramData\'
CommandLine|contains: 'C:\Users\'
CommandLine|contains: 'C:\Windows\Temp\'
CommandLine|contains: '\AppData\Local\Temp\'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`CommandLine`	match	`import` `%appdata%` corpus 4 (sigma 4) `%temp%` corpus 5 (sigma 5) `%tmp%` corpus 9 (sigma 9) `C:\ProgramData\` corpus 6 (sigma 6) `C:\Users\` corpus 5 (sigma 5) `C:\Windows\Temp\` corpus 4 (sigma 4) `\AppData\Local\Temp\` corpus 16 (sigma 16)
`Image`	ends_with	`\reg.exe` corpus 46 (sigma 46)
`OriginalFileName`	eq	`reg.exe` corpus 29 (sigma 29)