Potential Arbitrary Command Execution Via FTP.EXE

Severity: medium
Author: Victor Sergeev, oscd.community
Source: upstream

Detects execution of "ftp.exe" script with the "-s" or "/s" flag and any child processes ran by "ftp.exe".

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059` Command and Scripting Interpreter
Defense Evasion	`T1202` Indirect Command Execution

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `selection_parent`

ParentImage|endswith: '\ftp.exe'

Stage 2: `all of selection_child_img`

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

Stage 3: `all of selection_child_cli`

CommandLine|contains: '-s:'

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	`-s:`
`Image`	ends_with	`\ftp.exe` corpus 3 (sigma 3)
`OriginalFileName`	eq	`ftp.exe` corpus 2 (sigma 2)
`ParentImage`	ends_with	`\ftp.exe`