The challenge facing us today is twofold: not only is the digital footprint of the organizations we want to protect expanding and becoming more complex, but at the same time, it is harder to hire the right talent to work with us. Our organizations are using social media, file lockers, cloud SaaS applications, mobile devices, Bring Your Own Device (BYOD) and more. The question becomes now: how do we do more with less?
Force Multipliers: Open Source
Open Source software and Open Source INTelligence (OSINT) are powerful concepts in their own right, when we bring them together, we can really create some magic. There are many fantastic open source tools freely available which we can use to gather OSINT about our own organizations. We can take an “attacker’s eye view” of ourselves and use this to explore our exposure and develop effective mitigations.
Some of our favorite tools are:
Amass (https://github.com/OWASP/Amass) – a powerful tool for discovering subdomains from a domain
Visual Recon (https://wss.sh/en/blog/visual-recon-a-beginners-guide/) – this tool can be used to visualize all the web servers on an IP network range by taking a screenshot of the index page of each web server
Masscan (https://github.com/robertdavidgraham/masscan) – an exceptionally fast packet scanner which can help you enumerate large network ranges in a very short time
Nmap (https://nmap.org/) – a venerable tool (over 22 years old!), but still very useful. The service detection capabilities are second to none and are helpful for finding out exactly what is running on a particular port
Dnstwist (https://github.com/elceef/dnstwist) – this tool can help you identify typosquatted domains that an adversary may be using to target your organization
Google dorking (https://www.exploit-db.com/google-hacking-database) – Google dorking is a fantastic way to find information indexed by the search engine that might surprise you, such as login pages, configuration files and even credentials
There are also bigger frameworks that promise more features and capabilities such as:
SpiderFoot (https://www.spiderfoot.net/)
Intrigue (https://intrigue.io/)
DataSploit (https://github.com/DataSploit/datasploit)
Maltego community edition (https://www.paterva.com/web7/buy/maltego-clients/maltego-ce.php)
To provide fuel for these engines, there are many free data sets that can be used for investigating your own organization:
SHODAN (shodan.io) – the search engine for Internet-connected devices, essential for discovering what is connected to the public Internet. There is a limited, free version of this service
Hunter(www.hunter.io) – a useful search engine for discovering which email addresses are known as attributed to a particular organization. There is a limited, free version of this service
Certificate Transparency (https://crt.sh/) – this service allows you to search through issued SSL/TLS certificates to see which ones have been issued for a particular organization
Project Sonar(https://opendata.rapid7.com/) – Rapid7 collect a large amount of data about devices connected to the Internet and some of these collections are available for free
You can also roll your own custom tools to take advantage of these data sets by writing scripts in Python, Go or your own favourite language. This allows you the flexibility to get access to exactly the information you need to protect your own organization.
Attack Surface Reduction
So what can you use these tools for? One of the most useful things is to identify your own organization’s attack surface. For example, in terms of technology you can:
Identify online assets which should not be publicly accessible
Identify vulnerable services or software
Identify misconfigurations
You can also use, for example, Google dorking to detect if sensitive corporate information leaked outside of the organization. Through OSINT collection you can see if employees oversharing on social media or identify corporate information which should not be online.
Online Brand Security
An organization’s brand is a critical asset online, in order to protect it you can use tools like dnstwist to detect if attackers are generating domains similar to an organization’s own to target employees and customers. You may also want to investigate off-market app stores, that is, not run by the manufacturer, for mobile devices to see if there are apps present which impersonate your own organization’s apps for malicious purposes. Investigating social media sites also allows you to see if there are spoofed profiles attempting to impersonate, for example, customer care accounts which normally assist users who are have difficulties with a product or service. These impersonation accounts attempt to make unwitting users give up personal information or credentials or even install malware.
Summary
Whilst the Cyber talent gap is real and the challenges of defending organizations is growing, help is at hand. By harnessing the power of open source: both open source software and Open Source INTelligence (OSINT), we can gain insight into the attack surface of our own organizations by thinking like an attacker and viewing ourselves through the attacker’s eyes. This allows us to develop robust and resilient defenses which are informed by the real threats that we face.