The Importance of Out-of-Band Networks

Published: 2021-12-06
Last Updated: 2021-12-06 13:14:53 UTC
by Xavier Mertens (Version: 1)
0 comment(s)

Out-of-band (or "OoB") networks are usually dedicated to management tasks. Many security appliances and servers have dedicated management interfaces that are used to set up, control, and monitor the device. A best practice is to connect those management interfaces to a dedicated network that is not directly connected to the network used to carry applications/users' data. If a physically separated network is always best, a dedicated VLAN could do the job in most cases (if properly configured). What we typically find on OoB networks are:

  • Network devices (switches, routers, access-points)
  • IPMI (ILO, DRAC, etc)
  • Appliances management interfaces
  • Management interfaces of servers

They also carry sensitive protocols like SNMP, backup traffic to not interfere with the "production" traffic. OoB networks are, based on their criticality, pretty well hardened with very limited access through bastion hosts. Sometimes, they are so well protected that remote access is not allowed and could lead to critical situations like the recent Facebook downtime due to a BGP issue[1].

But OoB networks can also be used for other purposes: during a security incident. It's recommended to not allow Incident Handlers to use the corporate network to exchange information.

A few days ago, an interesting tweet has been posted by @vxunderground[2]. Apparently, the Ragnar Locker ransomware group was able to access a Slack channel used by the organization in charge of the investigations. 

(Image source: vxunderground's Twitter account)

As you can see on top of the screenshot, there is the classic Remote Desktop Client banner. Probably, an Incident Handler was connected to the Teams channel from a workstation on the compromised network and the attacker was still present... Teams is an "external service" and traffic to Teams is encrypted but if the client or the browser can be accessed, it's too late!

[1] https://blog.cloudflare.com/october-2021-facebook-outage/
[2] https://twitter.com/vxunderground/status/1466523987031302145?s=20

Xavier Mertens (@xme)
Senior ISC Handler - Freelance Cyber Security Consultant
PGP Key

0 comment(s)
ISC Stormcast For Monday, December 6th, 2021 https://isc.sans.edu/podcastdetail.html?id=7782

Comments

What's this all about ..?
password reveal .
<a hreaf="https://technolytical.com/">the social network</a> is described as follows because they respect your privacy and keep your data secure:

<a hreaf="https://technolytical.com/">the social network</a> is described as follows because they respect your privacy and keep your data secure. The social networks are not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go.

<a hreaf="https://technolytical.com/">the social network</a> is not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go. The social networks only collect the minimum amount of information required for the service that they provide. Your personal information is kept private, and is never shared with other companies without your permission
https://thehomestore.com.pk/
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
https://defineprogramming.com/
https://defineprogramming.com/
Enter comment here... a fake TeamViewer page, and that page led to a different type of malware. This week's infection involved a downloaded JavaScript (.js) file that led to Microsoft Installer packages (.msi files) containing other script that used free or open source programs.
distribute malware. Even if the URL listed on the ad shows a legitimate website, subsequent ad traffic can easily lead to a fake page. Different types of malware are distributed in this manner. I've seen IcedID (Bokbot), Gozi/ISFB, and various information stealers distributed through fake software websites that were provided through Google ad traffic. I submitted malicious files from this example to VirusTotal and found a low rate of detection, with some files not showing as malware at all. Additionally, domains associated with this infection frequently change. That might make it hard to detect.
https://clickercounter.org/
Enter corthrthmment here...

Diary Archives