Detect Employee Names in Elastic Security
Adversaries may gather employee names that can be used during targeting. Employee names can be used to derive email addresses as well as to help guide other reconnaissance efforts and craft more-believable lures. Adversaries may easily gather employee names since they may be readily available and exposed via online or other accessible data sets such as social media, LinkedIn, corporate websites, and press releases. Real-world threat actors including Kimsuky, Sandworm Team, and Silent Librarian have been observed collecting victim employee name information to support subsequent phishing campaigns, credential attacks, and social engineering operations. Detection is inherently challenging because this activity primarily occurs outside the victim's environment on public platforms. Effective detection pivots to monitoring organization-owned web properties for automated scraping, tracking OSINT tool execution on monitored endpoints, and identifying downstream artifacts such as systematic user enumeration via authentication systems.
MITRE ATT&CK
- Tactic
- Reconnaissance
- Technique
- T1589 Gather Victim Identity Information
- Sub-technique
- T1589.003 Employee Names
- Canonical reference
- https://attack.mitre.org/techniques/T1589/003/
Elastic Detection Query
/* Branch 1: OSINT harvesting tool execution on managed endpoints */
process where host.os.type == "windows" and
(
process.command_line like~ "*theHarvester*" or
process.command_line like~ "*recon-ng*" or
process.command_line like~ "*CrossLinked*" or
process.command_line like~ "*linkedin2username*" or
process.command_line like~ "*phonebook.cz*" or
process.command_line like~ "*SpiderFoot*" or
process.command_line like~ "*spiderfoot*" or
process.command_line like~ "*maltego*" or
process.name like~ "*theHarvester*" or
process.name like~ "*crosslinked*" or
process.name like~ "*linkedin2username*" or
process.name like~ "*recon-ng*" or
(
process.name like~ "python*.exe" and
(
process.command_line like~ "*linkedin*" or
process.command_line like~ "*harvest*" or
process.command_line like~ "*employee*" or
process.command_line like~ "*osint*"
)
)
)
/* Branch 2: Web directory scraping — deploy as Kibana Threshold Rule against proxy index */
/* Threshold rule config: index=logs-*, group_by=[source.ip], threshold count > 25 over 60m */
/* Filter: event.dataset:("proxy" OR "squid" OR "zscaler_proxy" OR "cisco_wsa") */
/* AND url.path: ("*\/team*" OR "*\/about*" OR "*\/staff*" OR "*\/employees*" */
/* OR "*\/directory*" OR "*\/people*" OR "*\/leadership*" */
/* OR "*\/management*" OR "*\/bios*" OR "*\/board*") */Detects employee name harvesting (T1589.003) via two branches. Branch 1 is an EQL process query detecting execution of known OSINT harvesting tools — theHarvester, recon-ng, CrossLinked, linkedin2username, SpiderFoot, and maltego — on managed Windows endpoints, including Python-invoked variants. Branch 2 is documented as a Kibana Threshold Rule (not EQL) because EQL lacks native per-IP aggregation across arbitrary time windows; deploy it separately against the proxy data view with source.ip grouping and a count threshold of >25 events in 60 minutes against employee directory URL patterns.
Data Sources
Required Tables
False Positives & Tuning
- Authorized red team or penetration testing operators running theHarvester, recon-ng, or similar OSINT tools as part of a sanctioned engagement — cross-reference against change management or pentest schedule before escalating
- Threat intelligence or brand monitoring teams using SpiderFoot or Maltego for external attack surface assessment against their own organization — validate against approved tooling registry
- HR automation or talent acquisition platforms running Python scripts that interact with LinkedIn APIs for org chart sync or recruiter workflows — validate process parent chain and network destinations
Other platforms for T1589.003
Testing Methodology
Validate this detection against 5 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1theHarvester Employee Name and Email Enumeration
Expected signal: Sysmon Event ID 1 (Linux auditd equivalent): process creation for 'theHarvester' or 'python3' with command line arguments '-d example.com -b google'. Sysmon Event ID 3 / auditd SYSCALL: outbound network connections to Google APIs and search endpoints. Sysmon Event ID 11: creation of /tmp/harvest_output.json. On Windows endpoints: DeviceProcessEvents with FileName=python.exe and ProcessCommandLine containing 'theHarvester' and '-b google'.
- Test 2CrossLinked LinkedIn Employee Name to Email Permutation
Expected signal: Sysmon Event ID 1: process create for python3 with CommandLine containing 'CrossLinked' or 'crosslinked' and '-f' and '{first}.{last}'. Sysmon Event ID 3: outbound DNS and TCP connections to linkedin.com and www.linkedin.com on port 443. Sysmon Event ID 11: file creation at /tmp/crosslinked_names.txt. DeviceProcessEvents (MDE): ProcessCommandLine containing 'crosslinked' or '{first}.{last}'.
- Test 3Corporate Team Page Automated Scraping Simulation
Expected signal: Sysmon Event ID 3 (Network Connect): repeated outbound connections to httpbin.org:443. Process creation for curl. In a real environment targeting a corporate web property: WAF/proxy logs showing 30+ requests to /team, /about-us, /staff URLs from the same source IP within 60 seconds with User-Agent 'Python-urllib/3.9'. CommonSecurityLog entries with RequestURL matching directory patterns.
- Test 4recon-ng LinkedIn Contacts Module Employee Enumeration
Expected signal: Sysmon Event ID 1: process create for recon-ng binary or python3 with recon-ng in command path. Sysmon Event ID 11: file creation in ~/.recon-ng/workspaces/employee_hunt/ including SQLite database data.db. Sysmon Event ID 3: outbound connections to linkedin.com, api.linkedin.com on port 443. DeviceProcessEvents: FileName containing 'recon-ng' or ProcessCommandLine containing 'recon-ng'.
- Test 5Hunter.io API Employee Name and Email Harvesting
Expected signal: Sysmon Event ID 3: outbound DNS query for api.hunter.io and TCP connection to api.hunter.io:443. Process creation for curl or python3 with api.hunter.io in command line arguments. In proxy/web access logs: GET requests to api.hunter.io/v2/domain-search with domain parameter. If monitoring DNS (Sysmon Event ID 22): DNS query for api.hunter.io.
References (10)
- https://attack.mitre.org/techniques/T1589/003/
- https://www.opm.gov/cybersecurity/cybersecurity-incidents/
- https://www.justice.gov/opa/pr/nine-iranians-charged-conducting-massive-cyber-theft-campaign-behalf-islamic-revolutionary
- https://www.cisa.gov/sites/default/files/publications/AA20-296A-Kimsuky_0.pdf
- https://github.com/laramies/theHarvester
- https://github.com/m8sec/CrossLinked
- https://github.com/lanmaster53/recon-ng
- https://docs.microsoft.com/en-us/azure/active-directory/reports-monitoring/reference-sign-ins-error-codes
- https://hunter.io/api-documentation/v2
- https://www.mandiant.com/resources/blog/apt29-domain-fronting-with-tor
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