Data exfiltration: Definition and prevention

Data exfiltration is the theft or unauthorized removal of online data. Cybercriminals commit data theft by accessing personal or corporate computers or mobile devices. The stolen data becomes a tool for blackmail, ransom, and reputational damage.

How does data exfiltration occur? It happens either through outsider attacks or insider threats. Both are equally dangerous.

Attacks outside an organization can start with hackers accessing the company’s network and injecting malware. Malicious software exfiltrates data to an external server. Hackers can then sell or publish it.

Insider threats can happen on purpose or because of careless behavior. A person in the organization might transfer the company’s sensitive information to their personal data storage to sell it to a hacker later. Cybercriminals can also trick an employee into giving such data away.

Cybercriminals use various techniques to steal sensitive information. These methods are constantly evolving and becoming harder to stop. The first step to prevent them is understanding the approaches that hackers use.

Social engineering and phishing attacks

Social engineering relies on psychological manipulation to trick people into revealing sensitive data. One of the most common social engineering techniques is phishing attacks. They lure victims into downloading malware and giving up their account credentials.

A typical phishing approach includes an email that appears to be from a trusted sender. For example, the sender might disguise themselves as a bank that informs clients about insufficient funds. Such email usually requires the user to immediately click a link or download a file attached to the email. Unfortunately, these links and attachments contain malware that steals the victim’s credentials. It can be a keylogger or a trojan.

Some hackers also launch targeted phishing attacks. They seek to steal data from a specific user, such as a senior company executive, a celebrity, or a politician.

Outsider threats

Outsider threats refer to dangers posed by malicious actors outside of an organization. Cybercriminals seek to infiltrate a company’s network and steal valuable information. What data exfiltration methods do they use?

• Piggybacking. It refers to an unauthorized use of a network. Piggybacking usually occurs when Wi-Fi has no password and anyone can access it. Hackers might also guess the network’s security key and enter it without the owner’s permission.
• Watering hole. A watering hole attack targets a specific group of people or an organization. This hacking technique tempts victims to visit a malicious website and download malware that can infect the whole network.
• Scareware. It’s a method that uses fear-mongering tactics to trick victims into downloading malicious software. Scareware malware typically hides beneath an aggressive pop-up or a banner that warns to take immediate action.
• Dumpster diving. A dumpster diving attack expands into the physical world. Hackers search through a person’s or a company’s discarded materials and look for valuable clues. Criminals then use their findings (such as pieces of paper with a company’s passwords) to access vulnerable information.
• Shoulder surfing. A hacker peeks over a victim’s shoulder to observe what they are doing on their device. A shoulder surfing attack aims to steal information such as credit card details, account passwords, and PIN codes.
• Pretexting. It’s a social engineering technique that uses fake scenarios to convince victims to give away their credentials or perform specific actions. In pretexting, hackers pretend to be trustworthy people such as co-workers, bank representatives, or government officials.
• Honey trap. With this technique, an attacker seduces a victim and later uses their romantic or sexual relationship as leverage to extract sensitive data.
• Baiting. This type of social engineering attack uses a false promise that lures victims into a trap. The classic example is an email claiming you have won 1,000,000 dollars.
• Diversion theft. It intercepts data delivery by tricking victims into sending information to the wrong address. Diversion thefts can happen online (for instance, a victim gets an incorrect email address that belongs to a hacker) and offline (a criminal readdresses a courier to another delivery location).
• Whaling. A whaling attack targets higher-ranking employees in a company. Disguised as senior executives, criminals try to steal sensitive data or money from the victims.
• Impersonation. A criminal pretends to be trustworthy to dupe targets into sharing their credentials or transferring money. The names hackers use include those of celebrities, government representatives, or higher-ranking coworkers of the victim.

Data extrusion through outbound emails

If cybercriminals gain access to a company’s internal network, they might use outbound emails to gain possession of sensitive information. A hacker gathers and forwards the exfiltrated data to their email address through text messages and file attachments.

Detecting data exfiltration through data egress traffic, such as outbound emails, can be challenging. They are a common and legitimate way of communication, so organizations might never spot that their data traveled to malicious actors.

Data theft through downloads to insecure devices

This tactic of digital data theft usually involves a person who has access to a company’s network. The insider uses a protected organization’s device to send sensitive information to their unmonitored gadget outside the organization. It could be a camera, an external drive, or a smartphone that has no restrictions by a firm’s security policies.

Data exfiltration through human error in the cloud

Online data clouds provide companies multiple benefits, such as scalable storage, collaboration possibilities, and digital encryption. Yet unsecure human behavior can throw these advantages away.

If an authorized person accesses the cloud without following the guidelines, they may open the door to an evil actor. Cybercriminals can install malware, change virtual machines, and submit malicious requests.

The effects of one data exfiltration attack can last for ages. After stealing sensitive information, hackers might use it to damage a company’s reputation. For example, potential clients could see the organization as incapable of protecting their personal data or intellectual property.

Data extrusion can also cause financial loss. Cybercriminals might steal a company’s credit accounts. They can use the stolen data to blackmail an organization for ransom, not to mention all the money a company will need to strengthen its online security.

Legal troubles are another negative outcome of data leakage. A company might face multiple lawsuits from furious customers. It may also have to deal with penalties for not complying with data protection regulations.

Data exfiltration causes serious fire. What mandatory security measures should organizations use to detect and prevent it?

Detecting a data breach can be like searching for a needle in a haystack. Malicious actors use advanced hacking techniques that can mask their attacks. A security breach might look like usual network traffic. To detect cybercriminals, organizations must implement tools that can track malicious activity in real time.

An intrusion detection system (IDS) is one of them. It monitors a network and searches for malicious traffic. When IDS detects something suspicious, it alerts the organization’s security teams.

Once the tool catches a threat, a company can analyze it with static or dynamic malware analysis tools. They let organizations understand the possible damage and strengthen internal data security systems.

Data loss prevention requires some effort. But not having it is too dangerous. Organizations that seek to mitigate the risk of data exfiltration should adopt practices such as:

• Conducting data risk assessments. They help organizations see the weakest parts of their internal network. Recognizing pain points allow companies to prepare for possible data exfiltration risks.
• Investing in cybersecurity tools. They can bolster protection against data loss. Combining such instruments as a next-generation firewall (NGFW), a security information and event management system (SIEM), and a virtual private network (VPN) can significantly improve corporate network security. They will help to avoid common threats, block unauthorized access, and encrypt digital data.
• Educating employees. Human error is the most common reason for a data breach. Educating employees about phishing attacks, the dangers of transferring data to unprotected devices, and the problems with weak passwords is essential. Frequent training about the best online safety practices is the key to improving workers’ awareness.
• Performing frequent data backups. Keeping all eggs in one basket is never a good idea. So if a company’s data is lost or stolen, having a backup is the go-to solution to restore it.
• Managing network access. Online security mechanisms such as multi-factor authentication help to ensure that only authorized people can access sensitive data.