Re: Measures of detecting breached email accounts

[Keenan Martinez <0000004218ecec53-dmarc-request () LISTSERV EDUCAUSE EDU>]

Frank,



Thank you for your feedback, I garner the procedure can be automated but is not 100% successful.



I question if there is more we can do besides enabling MFA, DKIM, DMARC and other procedure Universities utilise in 
reducing account breaches and spamming.



At our University, our policies govern that all employees must utilise MFA. However, due to limited resources I am 
reluctant to expand the policy to our student accounts. It leads the team to perform the process mentioned in my first 
email, of sorting logs via country.



I believe there should be (if a system already exists), which allows you to allow logins only via region. I.e. email 
account will only accept logins from your region (mine being the Caribbean) and deny login from other areas, with an 
option to request access. My view may be far fetched, but I think it would assist greatly with account breaches.



Regards,



From: The EDUCAUSE Security Constituent Group Listserv <SECURITY () LISTSERV EDUCAUSE EDU> on behalf of Frank Barton 
<bartonf () HUSSON EDU>
Reply-To: The EDUCAUSE Security Constituent Group Listserv <SECURITY () LISTSERV EDUCAUSE EDU>
Date: Tuesday, 5 December 2017 at 9:50 am
To: "SECURITY () LISTSERV EDUCAUSE EDU" <SECURITY () LISTSERV EDUCAUSE EDU>
Subject: Re: [SECURITY] Measures of detecting breached email accounts

We put a spam-filter on our outbound email queue, and have found that that is a pretty good indicator of detecting 
compromised accounts. The filter also emails us (me) on blocked outbound spam, and when I start hearing my phone go 
ding-ding-ding-ding-ding-ding-ding, it's never a good time.

We've also found that compromises tend to come in waves, and be "trackable". Once we identify a compromised account, we 
then look at logins, and start looking for patterns in other accounts. Matching IP addresses in a short window is a 
good indication. We also then found that there was typically a 2-step compromise pattern. The initial compromise would 
show up as a single login from an IP address that was not in the normal use pattern. a couple days later we would see 
the login that would then try to flood spam out to the interwebs.

We've tried to automate this as much as possible, but a lot of it falls under the german word "Gefuhlsache" it's a 
matter of feeling.

That being said, I did write a script that would pull down the last couple weeks of Google logins logs, and look for 
out-of-the country IPs, this had some success among our staff and faculty members during the academic year, but a lot 
less over breaks, and when looking at students.

Stepping away from account compromise, we run a, very locked down, SFTP server on the amazon cloud, one of the things I 
have installed is fail2ban. I've build up a manual list of netblocks that we just block outright from accessing the 
server. I am somewhat hesitant to expand that to other services, but the thought has crossed my mind.

Frank

On Mon, Dec 4, 2017 at 9:56 PM, Valdis Kletnieks <valdis.kletnieks () vt edu<mailto:valdis.kletnieks () vt edu>> wrote:
On Mon, 04 Dec 2017 23:19:28 +0000, Keenan Martinez said:

> I am inquiring about techniques members undertake to proactively detect
> breached email accounts and how the process of converting IP addresses to
> countries be simplified?

Doing exception analysis on successful *and failed* logins is a good start -
and done a *lot* more frequently than "monthly".  You'll very quickly learn to
tell the difference between dictionary attacks trying to get into *any* userid, and
targeted attacks on a specific user - if one of your VPs is hit overnight with 17 failed
login attempts from Ukraine while they're sleeping in the Carribean night, you have
a potential problem.

Another thing to monitor is for unusual traffic patterns, both inbound and outbound.
For instance, my userid gets a *lot* of inbound mail from software-related lists, and lots of
usually small outbound mail to pretty much all over the planet.  But if I suddenly send out
a series of 28 outbound emails that are 17M in size each, it might indicate that my userid
has been compromised and is being used to exfiltrate sensitive data.

Also, look at traffic levels for things other than email - http/https, ftp, and so on.  Suddenly
high traffic levels from a user/machine that hasn't been historically very active is a possible
sign of a problem - especially large volumes of outbound data indicating possible uploads
of sensitive info.

There's not a lot of "proactive detection" that you can really do - in most
cases, you're either reacting to logs/audit trails, or doing proactive stuff up
front to *prevent* the breach in the first place.

Stuff like the SANS "Securing the Human" is helpful to get your users up to speed.
Checking for easily broken passwords, enforcing stronger passwords and/or multi-factor
authentication for users with critical access, making sure that your users have their
machines patched and appropriate security/AV software installed and up to date..

etc etc etc.  All the usual "how to keep your users from being hacked/phished" stuff....



--
Frank Barton
Security+, ACMT
IT Systems Administrator
Husson University
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