Detection rules › Splunk

Windows Unusual FileZilla XML Config Access

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic identifies processes accessing FileZilla XML config files such as recentservers.xml and sitemanager.xml. It leverages Windows Security Event logs, specifically monitoring EventCode 4663, which tracks object access events. This activity is significant because it can indicate unauthorized access or manipulation of sensitive configuration files used by FileZilla, a popular FTP client. If confirmed malicious, this could lead to data exfiltration, credential theft, or further compromise of the system.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1552.001 Unsecured Credentials: Credentials In Files

Event coverage

ProviderEvent IDTitle
Security-Auditing4663An attempt was made to access an object.

Stages and Predicates

Stage 1: search

search NOT ProcessName IN ("C:\Program Files (x86)\\FileZilla FTP Client\\filezilla.exe", "C:\\Program Files (x86)\\Microsoft OneDrive\\OneDrive.exe", "C:\\Program Files\\FileZilla FTP Client\\filezilla.exe", "C:\\Program Files\\Microsoft OneDrive\\OneDrive.exe") EventCode=4663 file_path IN ("*FileZilla\\recentservers.xml*", "*FileZilla\\sitemanager.xml*")

Stage 2: stats

stats BY ObjectName, ObjectType, ProcessName, AccessMask, process_id, EventCode, Computer, Caller_User_Name

Stage 3: rename

rename

Stage 4: search

search

Stage 5: search

search

Stage 6: search

search `macro`

Exclusions

Top-level NOT(...) conjuncts — predicates this rule actively suppresses.

StageFieldKindExcluded values
1process_namein"C:\Program Files (x86)\\FileZilla FTP Client\\filezilla.exe", "C:\\Program Files (x86)\\Microsoft OneDrive\\OneDrive.exe", "C:\\Program Files\\FileZilla FTP Client\\filezilla.exe", "C:\\Program Files\\Microsoft OneDrive\\OneDrive.exe"

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.

FieldKindValues
EventCodeeq
  • 4663 corpus 16 (splunk 16)
file_pathin
  • "*FileZilla\\recentservers.xml*"
  • "*FileZilla\\sitemanager.xml*"

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.