PUA - 3Proxy Execution

Severity: high
Author: Florian Roth (Nextron Systems)
Source: upstream

Detects the use of 3proxy, a tiny free proxy server

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	`T1572` Protocol Tunneling

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `1 of selection_img`

Image|endswith: '\3proxy.exe'

Stage 2: `1 of selection_pe`

Description: '3proxy - tiny proxy server'

Stage 3: `1 of selection_params`

CommandLine|contains: '.exe -i127.0.0.1 -p'

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	`.exe -i127.0.0.1 -p`
`Description`	eq	`3proxy - tiny proxy server`
`Image`	ends_with	`\3proxy.exe`