Splunk Search

How to generate a malware search to find users with packets sent out every 1, 3, or 5 minutes for the last 24 hours?

edvornit
New Member

I'd like to find users with activity in every 1/3/5 minute bucket in the last 24 hours as the indication of possible malware/botnet beaconing.

Let's say I have sourcetype=firewall and bytes_out/packets_out for activity and src_user for user.

Any idea how to write such search?

0 Karma

somesoni2
Revered Legend

Something like this. You can update the span per your need.

index=YourINdex sourcetype=firewall | bucket span=1m _time | stats sum(bytes_out) as bytes_out sum(packets_out) as packets_out by _time activity src_user
0 Karma

edvornit
New Member

How would you filter it further to get only the users that have packets_out > 10 in every 5 min bucket?

0 Karma

somesoni2
Revered Legend

With current query, it's giving you total packets sent by activity-src_user combination for every minute. For get "only the users that have packets_out > 10 in every 5 min bucket", first change the span to 5m and use where clause to filter it.

index=YourINdex sourcetype=firewall | bucket span=5m _time | stats sum(bytes_out) as bytes_out sum(packets_out) as packets_out by _time activity src_user | where packets_out>10
0 Karma

edvornit
New Member

Yes, but it only gives users with activity in each bucket.

Let's say we have three buckets:
bucket1:
user1,user2,user3
bucket2:
user1,user4,user5
bucket3:
user1,user4,user6

So, I want to display only the usernames with activity in all buckets, so in this case it's only user1.

0 Karma
Get Updates on the Splunk Community!

Index This | What is broken 80% of the time by February?

December 2025 Edition   Hayyy Splunk Education Enthusiasts and the Eternally Curious!    We’re back with this ...

Unlock Faster Time-to-Value on Edge and Ingest Processor with New SPL2 Pipeline ...

Hello Splunk Community,   We're thrilled to share an exciting update that will help you manage your data more ...

Splunk MCP & Agentic AI: Machine Data Without Limits

Discover how the Splunk Model Context Protocol (MCP) Server can revolutionize the way your organization uses ...