Detection rules › Splunk
Attrib.exe Metasploit File Dropper (EDR)
Using attrib.exe, an adversary may display or change file attributes in order to bypass UAC restrictions. Metasploits file_dropper.rb, which is include in some payloads uses this to assist in removing artifacts
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1564 Hide Artifacts |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
id: '5976.12048'
title: Attrib.exe Metasploit File Dropper
description: 'Using attrib.exe, an adversary may display or change file attributes
in order to bypass UAC restrictions. Metasploits file_dropper.rb, which is include
in some payloads uses this to assist in removing artifacts. -- Software Association:
TargetCompany'
logic_format: Splunk
logic: ' `get_endpoint_data` `get_endpoint_data_edr` ((event_type IN ("childproc","netconn","proc"))
OR (TERM(ProcessRollup2) OR Type=Process) OR TERM(DeviceProcessEvents)) TERM(attrib)
AND TERM(dll) | regex process="attrib.+?\.dll" | table _time, host, user parent_*,
process, process_*, signature_id | bin span=1s | stats values(*) as * by _time,
host `hec_collect`'
techniques:
- defense-evasion:hide artifacts
technique_id:
- T1564
data_category:
- Process command-line parameters
- EDR Logs
references:
- https://github.com/rapid7/metasploit-framework/blob/master/lib/msf/core/exploit/file_dropper.rb
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_edr` ((event_type IN ("childproc","netconn","proc")) OR (TERM(ProcessRollup2) OR Type=Process) OR TERM(DeviceProcessEvents)) TERM(attrib) AND TERM(dll)
Stage 2: regex
| regex process="attrib.+?\.dll"
Stage 3: table
| table _time, host, user parent_*, process, process_*, signature_id
Stage 4: bucket
| bin span=1s
Stage 5: stats
| stats values(*) as * by _time, host `hec_collect`
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 |
|---|---|---|
event_type | in |
|
process | regex_match |
|
Search terms
Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.
| Stage | Term |
|---|---|
| 1 | TERM |
| 1 | ProcessRollup2 |
| 1 | TERM |
| 1 | DeviceProcessEvents |
| 1 | TERM |
| 1 | attrib |
| 1 | TERM |
| 1 | dll |