Use Of The SFTP.EXE Binary As A LOLBIN

SIGMA detection rule by Nasreddine Bencherchali (Nextron Systems) · NOASSERTION

Detects the usage of the "sftp.exe" binary as a LOLBIN by abusing the "-D" flag

title: Use Of The SFTP.EXE Binary As A LOLBIN
id: a85ffc3a-e8fd-4040-93bf-78aff284d801
status: test
description: Detects the usage of the "sftp.exe" binary as a LOLBIN by abusing the "-D" flag
references:
    - https://github.com/LOLBAS-Project/LOLBAS/pull/264
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-11-10
tags:
    - attack.execution
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\sftp.exe' # The "sftp.exe" located in the OpenSSH directory has no OriginalFileName :(
        CommandLine|contains:
            # Since "-D" is a valid flag for other usage we assume the user is going to enter a path
            # Either a full one like "C:\Windows\System32\calc.exe" or a relative one "..\..\..\Windows\System32\calc.exe"
            # In my testing you can't execute direct binaries by their name via this method (if you found a way please update the rule)
            - ' -D ..'
            - ' -D C:\'
    condition: selection
falsepositives:
    - Unknown
level: medium

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

9c9c288b-c6fb-444d-bdef-803a3ca10d3a

Propose edits, view related rules, and engage with the community through comments.

Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

[[ reason ]]

What does this mean?

Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

[[ reason ]]

What do these messages mean?

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

[[ currentRule.title ]]

Community Discussion