SMB (Windows File Sharing) Activity to the Internet
editSMB (Windows File Sharing) Activity to the Internet
editThis rule detects network events that may indicate the use of Windows file sharing (also called SMB or CIFS) traffic to the Internet. SMB is commonly used within networks to share files, printers, and other system resources amongst trusted systems. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or backdoor vector or for data exfiltration.
Rule type: query
Rule indices:
- auditbeat-*
- filebeat-*
- packetbeat-*
- logs-endpoint.events.*
Severity: high
Risk score: 73
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Network
- Threat Detection
- Initial Access
- Host
Version: 100 (version history)
Added (Elastic Stack release): 7.6.0
Last modified (Elastic Stack release): 8.5.0
Rule authors: Elastic
Rule license: Elastic License v2
Rule query
editevent.category:(network or network_traffic) and network.transport:tcp and (destination.port:(139 or 445) or event.dataset:zeek.smb) and source.ip:( 10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16 ) and not destination.ip:( 10.0.0.0/8 or 127.0.0.0/8 or 169.254.0.0/16 or 172.16.0.0/12 or 192.0.0.0/24 or 192.0.0.0/29 or 192.0.0.8/32 or 192.0.0.9/32 or 192.0.0.10/32 or 192.0.0.170/32 or 192.0.0.171/32 or 192.0.2.0/24 or 192.31.196.0/24 or 192.52.193.0/24 or 192.168.0.0/16 or 192.88.99.0/24 or 224.0.0.0/4 or 100.64.0.0/10 or 192.175.48.0/24 or 198.18.0.0/15 or 198.51.100.0/24 or 203.0.113.0/24 or 240.0.0.0/4 or "::1" or "FE80::/10" or "FF00::/8" )
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Initial Access
- ID: TA0001
- Reference URL: https://attack.mitre.org/tactics/TA0001/
-
Technique:
- Name: Exploit Public-Facing Application
- ID: T1190
- Reference URL: https://attack.mitre.org/techniques/T1190/
-
Tactic:
- Name: Exfiltration
- ID: TA0010
- Reference URL: https://attack.mitre.org/tactics/TA0010/
-
Technique:
- Name: Exfiltration Over Alternative Protocol
- ID: T1048
- Reference URL: https://attack.mitre.org/techniques/T1048/
Rule version history
edit- Version 100 (8.5.0 release)
-
- Formatting only
- Version 12 (8.4.0 release)
-
- Formatting only
- Version 11 (7.15.0 release)
-
- Formatting only
- Version 10 (7.14.0 release)
-
-
Updated query, changed from:
event.category:(network or network_traffic) and network.transport:tcp and (destination.port:(139 or 445) or event.dataset:zeek.smb) and source.ip:( 10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16 ) and not destination.ip:( 10.0.0.0/8 or 127.0.0.0/8 or 169.254.0.0/16 or 172.16.0.0/12 or 192.168.0.0/16 or 224.0.0.0/4 or "::1" or "FE80::/10" or "FF00::/8" )
-
- Version 8 (7.12.0 release)
-
- Formatting only
- Version 7 (7.11.2 release)
-
- Formatting only
- Version 6 (7.11.0 release)
-
-
Updated query, changed from:
event.category:(network or network_traffic) and network.transport:tcp and (destination.port:(139 or 445) or event.dataset:zeek.smb) and source.ip:(10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16) and not destination.ip:(10.0.0.0/8 or 127.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16 or "::1")
-
- Version 5 (7.10.0 release)
-
- Formatting only
- Version 4 (7.9.0 release)
-
-
Updated query, changed from:
network.transport:tcp and destination.port:(139 or 445) and source.ip:(10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16) and not destination.ip:(10.0.0.0/8 or 127.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16 or "::1")
-
- Version 3 (7.7.0 release)
-
-
Updated query, changed from:
network.transport: tcp and destination.port: (139 or 445) and ( network.direction: outbound or ( source.ip: (10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16) and not destination.ip: (10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16) ) )
-
- Version 2 (7.6.1 release)
-
- Removed auditbeat-*, packetbeat-*, and winlogbeat-* from the rule indices.