nanog mailing list archives

Re: Abuse Desks


From: Tom Beecher <beecher () beecher cc>
Date: Wed, 29 Apr 2020 10:12:07 -0400

IMO, the answer is balance.

- Handful of SSH connection attempts against a server. Nobody got in,
security hardening did it's job. I don't think that is worth reporting.
- Constant brute force SSH attempts from a given source over an extended
period of time, or a clear pattern of probing, yes, report that.

As much as some pound on the table and say there shouldn't be, there is
always going to be a level of background 'cruft' traffic between networks.
Forever. An argument was made somewhere in here that "scanning" is , by
itself, a problem. I disagree. There are many legitimate use cases for
certain types of scans, maps, etc. It's true that it sometimes can be
difficult to distinguish between a malicious scan and an innocent one.
Proposing a solution of "stop all scanning" is absolutely a baby/bathwater
angle.

I would also challenge those that say "Oh well all these companies should
have perfect flow logs and pay an army of engineers to analyze them for
these 5 specific TCP SYNs from 2 weeks ago." I would bet you probably
couldn't do that either.

On Tue, Apr 28, 2020 at 11:59 AM Mike Hammett <nanog () ics-il net> wrote:

I noticed over the weekend that a Fail2Ban instance's complain function
wasn't working. I fixed it. I've noticed a few things:

1) Abusix likes to return RIR abuse contact information. The vast majority
are LACNIC, but it also has kicked back a couple for APNIC and ARIN. When I
look up the compromised IP address in Abusix via the CLI, the APNIC and
ARIN ones return both ISP contact information and RIR information. When I
look them up on the RIR's whois, it just shows the ISP abuse information.
Weird, but so rare it's probably just an anomaly. However, almost
everything I see in LACNIC's region is returned with only the LACNIC abuse
information when the ones I've checked on LACNIC's whois list valid abuse
information for that prefix. Can anyone confirm they've seen similar
behavior out of Abusix? I reached out to them, but haven't heard back.
2) Digital Ocean hits my radar far more than any other entity.
3) Azure shows up a lot less than GCP or AWS, which are about similar to
each other.
4) Around 5% respond saying it's been addressed (or why it's not in the
event of security researchers) within a couple hours. The rest I don't
know. I've had a mix of small and large entities in that response.
5) HostGator seems to have an autoresponder (due to a 1 minute response)
that just indicates that you sent nothing actionable, despite the report
including the relevant log file entries.
6) Charter seems to have someone actually looking at it as it took them 16
- 17 hours to respond, but they say they don't have enough information to
act on, requesting relevant log file entries...  which were provided in the
initial report and are even included in their response. They request
relevant log file entries with the date, time, timezone, etc. all in the
body in plain text, which was delivered.
7) The LACNIC region has about 1/3 of my reports.



Do these mirror others' observations with security issues and how abuse
desks respond?



-----
Mike Hammett
Intelligent Computing Solutions
http://www.ics-il.com

Midwest-IX
http://www.midwest-ix.com


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