Cyber threat intelligence (CTI) sharing is a critical tool for security analysts. It takes the learnings from a single organization and shares it across the industry to strengthen the security practices of all.
By sharing CTI, security teams can alert each other to new findings across the threat landscape and flag active cybercrime campaigns and indicators of compromise (IOCs) that the cybersecurity community should be immediately aware of. As this intel spreads, organizations can work together to build upon each other’s defenses to combat the latest threat. This creates a herd-like immunity for networks as defensive capabilities are collectively raised.
Blue teams need to act more like red teams
A recent survey by Exabeam showed that 62 percent of blue teams have difficulty stopping red teams during adversary simulation exercises. A blue team is charged with defending one network. They have the benefit of knowing the ins and outs of their network better than any red team or cybercriminal, so they are well-equipped to spot abnormalities and IOCs and act fast to mitigate threats.
But blue teams have a bigger disadvantage: they mostly work in silos consisting only of members of their immediate team. They typically don’t share their threat intelligence with other security teams, vendors, or industry groups. This means they see cyber threats from a single lens. They lack the broader view of the real threat landscape external to their organization.
This disadvantage is where red teams and cybercriminals thrive. Not only do they choose the rules of the game – the when, where, and how the attack will be executed – they share their successes and failures with each other to constantly adapt and evolve tactics. They thrive in a communications-rich environment, sharing frameworks, toolkits, guidelines, exploits, and even offering each other customer support-like help.
For blue teams to move from defense to prevention, they need to take defense to the attacker’s front door. This proactive approach can only work by having timely, accurate, and contextual threat intelligence. And that requires a community, not a company. But many companies are hesitant to join the CTI community. The SANS 2020 Cyber Threat Intelligence Survey shows that more than 40% of respondents both produce and consume intelligence, leaving much room for improvement over the next few years.
Common challenges for beginning a cyber threat intelligence sharing program
One of the biggest challenges to intelligence sharing is that businesses don’t understand how sharing some of their network data can actually strengthen their own security over time. Much like the early days of open-source software, there’s a fear that if you have anything open to exposure it makes you inherently more vulnerable. But as open source eventually proved, more people collaborating in the open can lead to many positive outcomes, including better security.
Another major challenge is that blue teams don’t have the lawless luxury of sharing threat intelligence with reckless abandon: we have legal teams. And legal teams aren’t thrilled with the notion of admitting to IOCs on their network. And there is a lot of business-sensitive information that shouldn’t be shared, and the legal team is right to protect this.
The opportunity is in finding an appropriate line to walk, where you can share intelligence that contributes to bolstering cyber defense in the larger community without doing harm to your organization.
If you’re new to CTI sharing and want to get involved here are a few pieces of advice.
Clear it with your manager
If you or your organization are new to CTI sharing the first thing to do is to get your manager’s blessing before you move forward. Being overconfident in your organization’s appetite to share their network data (especially if they don’t understand the benefits) can be a costly, yet avoidable mistake.
Start sharing small
Don’t start by asking permission to share details on a data exfiltration event that currently has your company in crisis mode. Instead, ask if it’s ok to share a range of IPs that have been brute forcing logins on your site. Or perhaps you’ve seen a recent surge of phishing emails originating from a new domain and want to share that. Make continuous, small asks and report back any useful findings.
Share your experience when you can’t share intelligence
When you join a CTI group, you’re going to want to show that you’re an active, engaged member. But sometimes you just don’t have any useful intelligence to share. You can still add value to the group by lending your knowledge and experience. Your perspective might change someone’s mind on their process and make them a better practitioner, thus adding to the greater good.
Demonstrate value of sharing CTI
Tie your participation in CTI groups to any metrics that demonstrate your organization’s security posture has increased during that time. For example, show any time that participation in a CTI group has directly led to intelligence that helped decrease alerted events and helped your team get ahead of a new attack.
There’s a CTI group for everyone
From disinformation and dark web to medical devices and law enforcement, there’s a CTI segment for everything you ever wanted to be involved in. Some are invite-only, so the more active you are in public groups the more likely you’ll be asked to join groups that you’ve shown interest in or have provided useful intelligence about. These hyper-niche groups can provide big value to your organization as you can get expert consulting from top minds in the field.
The more data you have, the more points you can correlate faster. Joining a CTI sharing group gives you access to data you’d never even know about to inform better decision making when it comes to your defensive actions. More importantly, CTI sharing makes all organizations more secure and unites us under a common cause.