suspicious_network_connections_by_unsigned_macho.md

Suspicious Network Connections by Unsigned Mach-O

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Metadata

• Author: Elastic

• Description: This hunt aggregates by process ID and destination IP by the number of connections per hour over a period of time greater than a defined threshold. This may indicate suspicious network connections by unsigned Mach-O binaries.

• UUID: dc04d70a-80aa-4c3f-ad02-2b18d54af6d4

• Integration: endpoint

• Language: [ES|QL]

• Source File: Suspicious Network Connections by Unsigned Mach-O

Query

from logs-endpoint.events.network-*
| where @timestamp > now() - 7 day
| where host.os.family == "macos" and event.category == "network" and
  (process.code_signature.exists == false or process.code_signature.trusted != true) and
  /* excluding private IP ranges */
  not CIDR_MATCH(destination.ip, "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", "192.0.0.0/24", "192.0.0.0/29", "192.0.0.8/32", "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32", "192.0.0.171/32", "192.0.2.0/24", "192.31.196.0/24", "192.52.193.0/24", "192.168.0.0/16", "192.88.99.0/24", "224.0.0.0/4", "100.64.0.0/10", "192.175.48.0/24","198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "240.0.0.0/4", "::1","FE80::/10", "FF00::/8")
| keep source.bytes, destination.address, process.name, process.entity_id, @timestamp
 /* calc total duration, total MB out, and the number of connections per hour */
| stats total_bytes_out = sum(source.bytes), count_connections = count(*), start_time = min(@timestamp), end_time = max(@timestamp) by process.entity_id, destination.address, process.name
| eval dur = TO_DOUBLE(end_time)-TO_DOUBLE(start_time), duration_hours=TO_INT(dur/3600000), MB_out=TO_DOUBLE(total_bytes_out) / (1024*1024), number_of_con_per_hour = (count_connections / duration_hours)
| keep process.entity_id, process.name, duration_hours, destination.address, MB_out, count_connections, number_of_con_per_hour
/* threshold is set to 120 connections per minute, you can adjust it to your env/FP rate */
| where duration_hours >= 8 and number_of_con_per_hour >= 120

Notes

• This hunt returns a list of processes by entity_id and name that have a high number of connections per hour over a period of time greater than a defined threshold.
• Pivoting by process.entity_id will allow further investigation (parent process, hash, child processes, other network events etc.).

MITRE ATT&CK Techniques

• T1071

License

• Elastic License v2