Just a little bit of exposed personal data can go a long way for a hacker

Hackers today use our exposed personal data against us. More than 90% of the time, cyberattacks are specifically crafted from users’ public data. To a hacker and to cyber specialists in general, this exposed, publicly available information is known as OSINT, or Open-Source Intelligence. OSINT can be any publicly available information a hacker can find on a target, such as data from LinkedIn, Instagram, and other social media sites, data brokers, breach repositories, and elsewhere. Hackers use this data to craft and power social engineering attacks. It is the data that tells the attacker who is a vulnerable and valuable target, how best to contact them, how to establish trust, and how ultimately to trick, coerce, or manipulate them. Social engineering attacks fool people into performing a desired action and criminals use social engineering to lure targets into handing over personal information, opening malicious files, or granting access to sensitive data.

In this post, we highlight some of the ways in which bad actors use our information in social engineering campaigns. Understanding the various ways in which even a limited amount of exposed personal information can be weaponized by social engineers can help us not only become more vigilant and cautious but will hopefully also motivate us to take proactive measures to protect ourselves and our companies before attacks happen.

Hackers need—and harvest!—personal information to craft attacks

In order to identify, choose, and plan attacks against potential targets, threat actors must first conduct OSINT reconnaissance. Hackers have a variety of tools that automate this process. They begin by searching for information and selecting a vulnerable target, and then using the target’s data to create a compelling story that will trick them. The social engineer uses one of several means, such as an email, social media, or a phone call, to contact the target and establish trust. If the communication is convincing enough, the victim will be fooled and unwittingly click a malicious link or give the attacker sensitive information that will be used against them or their company. 

On account of the essential role that public data plays in social engineering attacks, it behooves us to be aware of, and especially limit, the amount of personal information we share online. The larger our digital footprint is, the larger our attack surface is and the more visible we are to social engineers. The more information attackers have on a target, the easier it is for them to craft convincing, and ultimately successful, social engineering attacks. The less visible we are, the less attractive we are to hackers and the less paths to compromise there are to be exploited.

While deleting oneself entirely from the internet in the 21st century is not viable, by carefully manicuring what you share and with whom you share it, you can significantly reduce your visible attack surface and prevent social engineering attacks.

Even a little bit of exposed information can be dangerous

Hackers don’t need much personal information to wreak havoc on your life. They can do a significant amount of damage with just your cell phone number. Typing your number into a people search site, for instance, can reveal your personal information to an attacker in just a few seconds. This information can then be used for social engineering, identity theft, doxing, or other malicious actions, such as taking over your email and other accounts. 

With only your phone number, a hacker can easily determine your email address. They can then contact your mobile provider and claim to be you, route your number to their phone, log into your email, click ‘forgot password,’ and have the reset link sent to them. Once they have your email account, all of your other accounts are potentially vulnerable. This is one reason to avoid using the same username and password across multiple accounts! 

Once acquired, a hacker could also decide to ‘spoof’ your phone number. This makes your number appear on a caller ID even though it is not you. Using this method, a bad actor can impersonate you to trick one of your friends or colleagues, or call you from a spoofed number, one that you may recognize or trust, in an attempt to socially engineer you or to record your voice for use in another scam.

The fact that a hacker can do so much with just a limited amount of information should make us think twice about what we share publicly, even if it’s only our phone number. To see some of your exposed personal data, get your free report below.

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Exposed data and credential compromise

Hackers can also do a lot of damage with exposed login credentials. Usernames, email addresses, and corresponding passwords become available on the dark web (and the public web!) once they have been involved in a data breach. You can find out if your personal data has been compromised in a breach by checking haveIbeenpwned.com, for example. Whenever this type of information gets exposed, it can leave users vulnerable to credential compromise.

Credential compromise, also known as ‘credential stuffing,’ happens when an attacker obtains a list of breached username and password pairs (“credentials”) from the dark web and then uses automated scripts or ‘bots’ to test them on dozens or even hundreds of website login forms with the goal of gaining access to user accounts. There are massive lists of breached credentials available to hackers on the black market and, since most people reuse passwords across different accounts, it is inevitable that some of these credentials will work on other accounts, either personal or corporate.

Once hackers have access to a customer account through credential stuffing, they can use the account for various nefarious purposes such as stealing assets, making purchases, or obtaining more personal information that can be sold to other hackers. If the breached credentials belong to an employee, the hacker can use that access to compromise a company’s systems and assets. 

Since credential compromise relies on the reuse of passwords, avoiding the reuse of the same or similar passwords across different accounts is critical. Always use strong passwords that are difficult to guess and change them frequently. Additionally, using multi-factor authentication, which requires users to authenticate their login with something they physically have and something they personally know, is a good defense against credential stuffing since an attacker’s bots cannot replicate this validation method. 

Recent real-world examples reveal the dangers of exposed personal data for companies

Companies should be especially wary of the role exposed personal data of employees plays in cyberattacks. Three recent examples that made headlines highlight how just a limited amount of exposed employee information can be used to craft a successful social engineering campaign and breach organizations. 

Twilio and Cloudflare

In August, hackers targeted two security-sensitive companies, Twilio and Cloudflare, as part of a larger ongoing campaign dubbed “Oktapus” that ultimately compromised more than 130 organizations and netted the attackers nearly 10,000 login credentials. In the case of Twilio, the hackers began by cross referencing employee public data from Twilio’s LinkedIn roster (the starting point of most attacks) against existing exposed 3rd party breach data sets (e.g., haveibeenpwnd.com) and data broker data (e.g., white pages). This gave the attackers a list of personal information of employees to target. The hackers then created a fake domain and login page that looked like Twilio’s (twilio-sso.com or twilio-okta.com). Using the acquired personal data, they then sent text messages to employees, which appeared as official company communications. The link in the SMS message directed the employees to the attackers’ fake landing page that impersonated their company’s sign-in page. When the employees entered their corporate login credentials and two-factor codes on the fake page, they ended up handing them over to the attackers, who then used those valid credentials on the actual Twilio login page to access the systems illegally. 

exposed personal data

Although Cloudflare was also targeted in this way, they were able to stop the breach through their use of FIDO MFA keys. Even though they were able to keep the attackers from accessing their systems through advanced security practices, Cloudflare’s CEO, senior security engineer, and incident response leader stated that “This was a sophisticated attack targeting employees and systems in such a way that we believe most organizations would be likely to be breached.”

Indeed, the exposed personal data used to power the Oktapus attacks shows how dangerous even a small amount of public data can be in the hands of a social engineer.

Cisco 

In another example from May of this year, the corporate network of multinational security company Cisco was breached by hackers with links to both the Lapsus$ and Yanluowang ransomware gangs. In this case, the hackers acquired the username or email address of a Cisco employee’s Google account along with the employee’s cell phone number. They targeted the employee’s mobile device with repeated voice phishing attacks with the goal of taking over the Google account. The employee was using a personal Google account that was syncing company login credentials via Google Chrome’s password manager. The account was protected by multi-factor authentication (MFA), however, so the hackers posed as people from the technical support departments of well-known companies and sent the employee a barrage of MFA push requests until the target, out of fatigue, finally agreed to one of them. This gave the attackers access to the Cisco VPN through the user’s account. From there the attackers were able to gain further access, escalate privileges, and drop payloads before being slowed and contained by Cisco. The TTPs (techniques, tactics, and procedures) used in the attack were consistent with pre-ransomware activity.

Uber 

Most recently, the ride-hailing company Uber was breached by a hacker thought to be linked to the Lapsus$ group, who gained initial access by socially engineering an Uber contractor. The attacker had apparently acquired the corporate password of this contractor on the dark web after it had been exposed through malware on the contractor’s personal device. The attacker then repeatedly tried to login to the contractor’s Uber account, which sent multiple two-factor login approval requests to the contractor’s phone.  Finally, the hacker posed as Uber IT and sent a message asking the contractor to approve the sign-in. After successfully exhausting the contractor, the approval was granted, and this provided the hacker with the valid credentials needed to gain access to Uber’s VPN. Once inside, the hacker found a network share that had PowerShell scripts. One of these scripts contained admin credentials for Thycotic [a privileged access management solution]. Once the hacker had access to this, he was able to get access to all other internal systems by using their passwords. 

The Uber hack is a prime example of how, with only a limited amount of exposed personal data and some social engineering, a hacker can easily trick, manipulate, or coerce a human and compromise a company’s systems. See our key takeaways and remediation recommendations.

Limiting exposed personal data to prevent attacks

The examples provided here illustrate some of the common ways our personal information can be successfully weaponized by today’s hackers. It is now more urgent than ever for people and companies to know and manage their exposed public information proactively to help prevent attacks. Attackers are opportunists who care about their ROI. By limiting exposed personal data, it becomes more difficult and therefore more expensive for threat actors to succeed in social engineering attacks. Companies that recognize this fact pattern and take action to protect their employees will be more likely to avoid expensive and damaging breaches.