Files
splunk-security_content/detections/endpoint/detect_webshell_exploit_behavior.yml
2023-11-16 20:33:10 +00:00

97 lines
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YAML

name: Detect Webshell Exploit Behavior
id: 22597426-6dbd-49bd-bcdc-4ec19857192f
version: 2
date: '2023-07-10'
author: Steven Dick
status: production
type: TTP
description: This search is used to detect the abuse of web applications by adversaries.
Adversaries may install a backdoor or script onto web servers by exploiting known
vulnerabilities or misconfigruations. Web shells are used to establish persistent
access to systems and provide a set of executable functions or a command-line interface
on the system hosting the Web server.
data_source:
- Sysmon Event ID 1
search: '| tstats `security_content_summariesonly` count max(_time) as lastTime, min(_time)
as firstTime from datamodel=Endpoint.Processes where (Processes.process_name IN
("arp.exe","at.exe","bash.exe","bitsadmin.exe","certutil.exe","cmd.exe","cscript.exe",
"dsget.exe","dsquery.exe","find.exe","findstr.exe","fsutil.exe","hostname.exe","ipconfig.exe","ksh.exe","nbstat.exe",
"net.exe","net1.exe","netdom.exe","netsh.exe","netstat.exe","nltest.exe","nslookup.exe","ntdsutil.exe","pathping.exe",
"ping.exe","powershell.exe","pwsh.exe","qprocess.exe","query.exe","qwinsta.exe","reg.exe","rundll32.exe","sc.exe",
"scrcons.exe","schtasks.exe","sh.exe","systeminfo.exe","tasklist.exe","tracert.exe","ver.exe","vssadmin.exe",
"wevtutil.exe","whoami.exe","wmic.exe","wscript.exe","wusa.exe","zsh.exe") AND Processes.parent_process_name
IN ("w3wp.exe", "http*.exe", "nginx*.exe", "php*.exe", "php-cgi*.exe","tomcat*.exe"))
by Processes.dest,Processes.user,Processes.parent_process,Processes.parent_process_name,Processes.process,Processes.process_name
| `drop_dm_object_name("Processes")` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
| `detect_webshell_exploit_behavior_filter`'
how_to_implement: The detection is based on data that originates from Endpoint Detection
and Response (EDR) agents. These agents are designed to provide security-related
telemetry from the endpoints where the agent is installed. To implement this search,
you must ingest logs that contain the process GUID, process name, and parent process.
Additionally, you must ingest complete command-line executions. These logs must
be processed using the appropriate Splunk Technology Add-ons that are specific to
the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
data model. Use the Splunk Common Information Model (CIM) to normalize the field
names and speed up the data modeling process.
known_false_positives: Legitimate OS functions called by vendor applications, baseline
the environment and filter before enabling. Recommend throttle by dest/process_name
references:
- https://attack.mitre.org/techniques/T1505/003/
- https://github.com/nsacyber/Mitigating-Web-Shells
- https://www.hackingarticles.in/multiple-ways-to-exploit-tomcat-manager/
tags:
analytic_story:
- ProxyNotShell
- ProxyShell
- CISA AA22-257A
- HAFNIUM Group
- BlackByte Ransomware
- CISA AA22-264A
- Citrix ShareFile RCE CVE-2023-24489
- Flax Typhoon
- WS FTP Server Critical Vulnerabilities
- SysAid On-Prem Software CVE-2023-47246 Vulnerability
asset_type: Endpoint
confidence: 80
impact: 100
message: Webshell Exploit Behavior - $parent_process_name$ spawned $process_name$
on $dest$.
mitre_attack_id:
- T1505
- T1505.003
observable:
- name: user
type: User
role:
- Victim
- name: dest
type: Endpoint
role:
- Victim
- name: process_name
type: Process
role:
- Attacker
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- _time
- Processes.dest
- Processes.user
- Processes.parent_process
- Processes.parent_process_name
- Processes.process
- Processes.process_name
risk_score: 80
security_domain: endpoint
supported_tas:
- Splunk_TA_microsoft_sysmon
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1505.003/generic_webshell_exploit/generic_webshell_exploit.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: xmlwineventlog