Saturday Security Brief

Topics: Attack Surface Management, Active iMessage exploit targetting journalists, Academic research on unique EM attack vectors for air-gapped systems.

Any feedback or thoughts on the experience of receiving and discussing news through this brief or in general are welcome. I'm curious about this form of staying informed so I want to experiment. (Thanks again for the suggestion to post the topics as comments.)

Attack Surface Management

This concept is about ensuring that your network is equipped to handle the many issues that arise from accommodating various "Servers, IoT devices, old VPSs, forgotten environments, misconfigured services and unknown exposed assets" with an enterprise environment. Some of the wisdom here can be applied better think about protecting our personal networks as well. Outdated phones, computers, wifi extenders, and more can be a foothold for outside attackers to retain persistant access. Consider taking steps to migigate and avoid potential harm from untamed devices.

Consider putting certain devices on the guest network if your router supports doing so and has extra rules for devices on that network so they can't cause damage to your other devices directly.

"A report from 2016 predicted that 30% of all data breaches by 2020 will be the result of shadow IT resources: systems, devices, software, apps and services that aren’t approved, and in use without the organization’s security team’s knowledge. But shadow IT isn’t the only area where security and IT teams face issues with tracking and visibility."

Attack Surface Management: You Can’t Secure What You Can’t See ~ Security Trails

Multiple Journalists Hacked with ‘Zero-Click’ iMessage Exploit

Mobile spyware is continuing to evolve and tend towards professional solutions. Recently this technology has been abused to conduct espionage on journalists of major networks. Where once these exploits typically required some mistaken click from the user, new developments are allowing their activities without any trace or requiring interaction from the target.

"NSO Group’s Pegasus spyware is a mobile phone surveillance solution that enables customers to remotely exploit and monitor devices. The company is a prolific seller of surveillance technology to governments around the world, and its products have been regularly linked to surveillance abuses."

"In July and August 2020, government operatives used NSO Group’s Pegasus spyware to hack 36 personal phones belonging to journalists, producers, anchors, and executives at Al Jazeera. The personal phone of a journalist at London-based Al Araby TV was also hacked."

"The journalists were hacked by four Pegasus operators, including one operator MONARCHY that we attribute to Saudi Arabia, and one operator SNEAKY KESTREL that we attribute to the United Arab Emirates."

"More recently, NSO Group is shifting towards zero-click exploits and network-based attacks that allow its government clients to break into phones without any interaction from the target, and without leaving any visible traces."

The Great iPwn Journalists Hacked with Suspected NSO Group iMessage ‘Zero-Click’ Exploit ~ Citizen Lab

Security researchers exfiltrate data from air-gapped systems by measuring the vibrations made by PC fans.

Besides this potential exploit the article mentions past research done by Guri and his team which is worth checking out, like:

• LED-it-Go - exfiltrate data from air-gapped systems via an HDD's activity LED

• AirHopper - use the local GPU card to emit electromagnetic signals to a nearby mobile phone, also used to steal data

• MAGNETO & ODINI - steal data from Faraday cage-protected systems

• PowerHammer - steal data from air-gapped systems using power lines

• BRIGHTNESS - steal data from air-gapped systems using screen brightness variations

"Academics from an Israeli university have proven the feasibility of using fans installed inside a computer to create controlled vibrations that can be used to steal data from air-gapped systems."

Academics steal data from air-gapped systems using PC fan vibrations ~ Zdnet

Good Practices

"Hundreds of popular websites now offer some form of multi-factor authentication (MFA), which can help users safeguard access to accounts when their password is breached or stolen. But people who don’t take advantage of these added safeguards may find it far more difficult to regain access when their account gets hacked, because increasingly thieves will enable multi-factor options and tie the account to a device they control. Here’s the story of one such incident."

Turn on MFA Before Crooks Do It For You ~ Krebs on Security

Friday Security Brief

This release is trial for a weekly security brief compiled from trusted sources that encourage a general awareness of cyber security issues. I'm still not sure about how to do this so any thoughts or feedback will be appreciated.

Brexit deal mandates a limit to security standards

"In what is surely an unthinking cut-and-paste issue, page 921 of the Brexit deal mandates the use of SHA-1 and 1024-bit RSA:"

Brexit Deal Mandates Old Insecure Crypto Algorithms ~ Schneier on Security

FBI Warns of Hijacked Security Devices being exploited for Swatting

"Stolen email passwords are being used to hijack smart home security systems to “swat” unsuspecting users, the Federal Bureau of Investigation warned this week. The announcement comes after concerned device manufacturers alerted law enforcement about the issue."

FBI Warn Hackers are Using Hijacked Home Security Devices for Swatting ~ Threatpost

A look back at some email attacks of 2020

"In 2020, our spam folders bulged with malware-laced emails, phishing lures linking to ransomware schemes, impersonation attacks, spoofed brand and fake domain missives, and dubious requests from legit-sounding companies. So, what defined 2020 in spam?"

Inbox Attacks: The Miserable Year (2020) That Was ~ Threatpost

SolarWinds hackers accessed Microsoft source code

"The hackers behind the SolarWinds supply chain attack managed to escalate access inside Microsoft's internal network and gain access to a small number of internal accounts, which they used to access Microsoft source code repositories, the company said on Thursday."

SolarWinds hackers accessed Microsoft source code ~ Zdnet

CISA updates SolarWinds guidance

"The US Cybersecurity and Infrastructure Security Agency has updated its official guidance for dealing with the fallout from the SolarWinds supply chain attack.

In an update posted late last night, CISA said that all US government agencies that still run SolarWinds Orion platforms must update to the latest 2020.2.1HF2 version by the end of the year."

CISA updates SolarWinds guidance, tells US govt agencies to update right away

I'm attempting to provision two mirror staging and production environments for a future SaaS application that we're close to launching as a company, and I'd like to get some feedback on the provisioning script I've created that takes a default VPS from our hosting provider, DigitalOcean, and readies it for being a secure hosting environment for our application instance (which runs inside Docker, and persists data to an unrelated managed database).

I'm sticking with a simple infrastructure architecture at the moment: A single VPS which runs both nginx and the application instance inside a containerised docker service as mentioned earlier. There's no load balancers or server duplication at this point. @Emerald_Knight very kindly provided me in the Tildes Discord with some overall guidance about what to aim for when configuring a server (limit damage as best as possible, limit access when an attack occurs)—so I've tried to be thoughtful and integrate that paradigm where possible (disabling root login, etc).

I’m not a DevOps or sysadmin-oriented person by trade—I stick to programming most of the time—but this role falls to me as the technical person in this business; so the last few days has been a lot of reading and readying. I’ll run through the provisioning flow step by step. Oh, and for reference, Ubuntu 20.04 LTS.

First step is self-explanatory.

#!/bin/sh

# Name of the user to create and grant privileges to.
USERNAME_OF_ACCOUNT=

sudo apt-get -qq update
sudo apt install -qq --yes nginx
sudo systemctl restart nginx

Next, create my sudo user, add them to the groups needed, require a password change on first login, then copy across any provided authorised keys from the root user which you can configure to be seeded to the VPS in the DigitalOcean management console.

useradd --create-home --shell "/bin/bash" --groups sudo,www-data "${USERNAME_OF_ACCOUNT}"
passwd --delete $USERNAME_OF_ACCOUNT
chage --lastday 0 $USERNAME_OF_ACCOUNT

HOME_DIR="$(eval echo ~${USERNAME_OF_ACCOUNT})"
mkdir --parents "${HOME_DIR}/.ssh"
cp /root/.ssh/authorized_keys "${HOME_DIR}/.ssh"

chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys
chown --recursive "${USERNAME_OF_ACCOUNT}":"${USERNAME_OF_ACCOUNT}" "${HOME_DIR}/.ssh"

sudo chmod 775 -R /var/www
sudo chown -R $USERNAME_OF_ACCOUNT /var/www
rm -rf /var/www/html

Installation of docker, and run it as a service, ensure the created user is added to the docker group.

sudo apt-get install -qq --yes \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg-agent \
    software-properties-common

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo apt-key fingerprint 0EBFCD88

sudo add-apt-repository --yes \
   "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
   $(lsb_release -cs) \
   stable"

sudo apt-get -qq update
sudo apt install -qq --yes docker-ce docker-ce-cli containerd.io

# Only add a group if it does not exist
sudo getent group docker || sudo groupadd docker
sudo usermod -aG docker $USERNAME_OF_ACCOUNT

# Enable docker
sudo systemctl enable docker

sudo curl -L "https://github.com/docker/compose/releases/download/1.27.4/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose
sudo ln -s /usr/local/bin/docker-compose /usr/bin/docker-compose
docker-compose --version

Disable root logins and any form of password-based authentication by altering sshd_config.

sed -i '/^PermitRootLogin/s/yes/no/' /etc/ssh/sshd_config
sed -i '/^PasswordAuthentication/s/yes/no/' /etc/ssh/sshd_config
sed -i '/^ChallengeResponseAuthentication/s/yes/no/' /etc/ssh/sshd_config

Configure the firewall and fail2ban.

sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow ssh
sudo ufw allow http
sudo ufw allow https
sudo ufw reload
sudo ufw --force enable && sudo ufw status verbose

sudo apt-get -qq install --yes fail2ban
sudo systemctl enable fail2ban
sudo systemctl start fail2ban

Swapfiles.

sudo fallocate -l 1G /swapfile && ls -lh /swapfile
sudo chmod 0600 /swapfile && ls -lh /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile && sudo swapon --show
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

Unattended updates, and restart the ssh daemon.

sudo apt install -qq unattended-upgrades
sudo systemctl restart ssh

Some questions

You can assume these questions are cost-benefit focused, i.e. is it worth my time to investigate this, versus something else that may have better gains given my limited time.

1. Obviously, any critiques of the above provisioning process are appreciated—both on the micro level of criticising particular lines, or zooming out and saying “well why don’t you do this instead…”. I can’t know what I don’t know.

2. Is it worth investigating tools such as ss or lynis (https://github.com/CISOfy/lynis) to perform server auditing? I don’t have to meet any compliance requirements at this point.

3. Do I get any meaningful increase in security by implementing 2FA on login here using google authenticator? As far as I can see, as long as I'm using best practices to actually ssh into our boxes, then the likeliest risk profile for unwanted access probably isn’t via the authentication mechanism I use personally to access my servers.

4. Am I missing anything here? Beyond the provisioning script itself, I adhere to best practices around storing and generating passwords and ssh keys.

Some notes and comments

1. Eventually I'll use the hosting provider's API to spin up and spin down VPS's on the fly via a custom management application, which gives me an opportunity to programmatically execute the provisioning script above and run some over pre- and post-provisioning things, like deployment of the application and so forth.

2. Usage alerts and monitoring is configured within DigitalOcean's console, and alerts are sent to our business' Slack for me to action as needed. Currently, I’m settling on the following alerts:
   1. Server CPU utilisation greater than 80% for 5 minutes.
   2. Server memory usage greater than 80% for 5 minutes.
   3. I’m also looking at setting up daily fail2ban status alerts if needed.