PUA - Fast Reverse Proxy (FRP) Execution

Severity: high
Author: frack113, Florian Roth
Source: upstream

Detects the use of Fast Reverse Proxy. frp is a fast reverse proxy to help you expose a local server behind a NAT or firewall to the Internet.

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	`T1090` Proxy

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `1 of selection_img`

or:
Image|endswith: '\frpc.exe'
Image|endswith: '\frps.exe'

Stage 2: `1 of selection_cli`

CommandLine|contains: '\frpc.ini'

Stage 3: `1 of selection_hashes`

or:
Hashes|contains: 'MD5=7D9C233B8C9E3F0EA290D2B84593C842'
Hashes|contains: 'SHA1=06DDC9280E1F1810677935A2477012960905942F'
Hashes|contains: 'SHA256=57B0936B8D336D8E981C169466A15A5FD21A7D5A2C7DAF62D5E142EE860E387C'

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	`\frpc.ini`
`Hashes`	match	`MD5=7D9C233B8C9E3F0EA290D2B84593C842` `SHA1=06DDC9280E1F1810677935A2477012960905942F` `SHA256=57B0936B8D336D8E981C169466A15A5FD21A7D5A2C7DAF62D5E142EE860E387C`
`Image`	ends_with	`\frpc.exe` `\frps.exe`