Rare SMB Connection to the Internet
editRare SMB Connection to the Internet
editThis rule detects rare internet network connections via the SMB protocol. SMB is commonly used to leak NTLM credentials via rogue UNC path injection.
Rule type: new_terms
Rule indices:
- logs-endpoint.events.network-*
- winlogbeat-*
- logs-windows.sysmon_operational-*
- endgame-*
- logs-m365_defender.event-*
- logs-sentinel_one_cloud_funnel.*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Exfiltration
- Data Source: Elastic Endgame
- Data Source: Elastic Defend
- Data Source: Microsoft Defender for Endpoint
- Data Source: Sysmon
- Data Source: SentinelOne
Version: 6
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editevent.category:network and host.os.type:windows and process.pid:4 and
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
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"
)
Framework: MITRE ATT&CKTM
-
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/