What is PII Data?

What Is PII Data in Cybersecurity?

PII (Personally Identifiable Information) data is any information that may be used to tell who someone is, either by itself or when combined with other information. Some examples of PII data are passport or Social Security numbers, as well as quasi-identifiers that might be used to identify a person, like combining a date of birth with a city or postal code.

No single data category is always safe because identifiability depends on the context. A birth date, gender, or postal code may seem harmless on its own, but when combined with other information, it can be used to identify someone. You need to look at each combination of PII data to see how likely it is to be re-identified.

Why Securing PII Is Important

Companies that don’t protect their customers’ and employees’ PII may suffer legal action, data breaches, or other cybersecurity threats. We’ll go into more detail about these consequences below:

Regulatory Compliance

Recent data privacy rules have imposed strict requirements on how to handle PII correctly. For GDPR violations such as insufficient consent processes or breaking someone’s privacy rights, companies can be fined up to €20 million or 4% of their global annual revenue (whichever is greater). Since it was launched in 2018, GDPR fines have reached $6.2 billion.

The California Consumer Privacy Act (CCPA) and Canada’s Personal Information Protection and Electronic Documents Act (PIPEDA) have similar penalties. Companies have to pay $183 for each record of customer PII, like names and Social Security numbers. For employee PII, they have to pay $181.

Costs for incident response, legal fees, regulatory fines, and downtime for operations are also part of the financial impact.

Data Breaches and Other Cybersecurity Risks

The average cost of a data breach in the world was $4.9 million in 2024, which was 10% more than in 2023. 88% of data breaches involve stolen credentials, which shows how exposed PII can lead to bigger cyberattacks.

Cybercriminals can use stolen PII to launch credential stuffing attacks, social engineering campaigns, and advanced persistent threats (APTs) that can put the entire infrastructure of a business at risk.

Tax IDs, email addresses, phone numbers, and home addresses are examples of customer PII that is stolen in 46% of all data breaches. This number shows why PII is the most important target for hackers.

The Different Types of PII

Sensitive (direct) and non-sensitive (indirect) identifiers are two groups of PII. Sensitive identifiers may uniquely identify people, but non-sensitive identifiers can’t. If these IDs were compromised, they could cause harm.

Today’s technology has brought about a host of new digital identifiers that traditional systems weren’t designed to handle. This is yet another reason why organizations need to rethink how they categorize and manage information.

Sensitive PII (Direct Identifiers)

Sensitive PII is private information that can immediately identify a person and could cause significant harm if it gets out or is stolen. This category comprises information that criminals can use right away to steal someone’s identity or commit financial fraud.

Financial and Government Identifiers:

• Social Security numbers (SSN) and taxpayer numbers
• Driver’s license and government-issued IDs
• Passport and visa documentation
• Bank account numbers and credit card information

Biometric and Medical Data:

• Fingerprints, retinal scans, and facial recognition
• Medical records and health insurance information
• Genetic information and DNA profiles
• Mental health records and treatment history

Non-Sensitive PII (Indirect Identifiers)

Non-sensitive PII is personal information that, if released or stolen, wouldn’t harm a person on its own. But when paired with other pieces of information, non-sensitive PII can reveal your identity for malicious purposes.

Contact and Demographic Information:

• Full names and aliases
• Email addresses and phone numbers
• Home addresses and postal codes
• Date and place of birth

Professional and Educational Information:

• Job titles and company name
• Educational background and institutions
• Professional certifications and licenses
• Social media profiles and online presence

Emerging PII Categories

Modern technology has broadened our understanding of Personally Identifiable Information (PII) to encompass digital identifiers that older frameworks didn’t foresee. For example, the National Institute of Standards and Technology (NIST) acknowledges linked information that includes technical assets like IP addresses and MAC addresses.

These identifiers help maintain consistent ties to specific individuals or small groups. Additionally, other emerging types of PII are becoming increasingly significant:

Technologies for Digital Fingerprints:

• Unique hardware IDs and device fingerprints
• Browser fingerprints and tracking pixels
• Behavioral biometrics like keystroke patterns and mouse movements
• Voice recognition patterns and speech analysis data

Location and IoT Data:

• GPS coordinates and location history
• Smart device data and Internet of Things (IoT) IDs
• Vehicle telematics and transportation patterns
• Environmental sensor data linked to a person

How PII Is Collected and Stored

Organizations collect PII through conversations with customers and automated tools that capture data. This includes integration with third-party services and even technologies that discreetly monitor activities across digital platforms.

Today, data collection occurs in both organized and more freeform settings, which can make it tricky for businesses to keep track of personal information. Security leaders often face challenges in ensuring they have a clear view and control over the data they collect and manage.

Primary Methods to Collect PII

Companies gather PII data every time you swipe a card at the checkout, fill out an online form, or tap “accept” on a mobile app. They store these details so they can:

• Complete transactions quickly and accurately
• Personalize services (think tailored product recommendations or faster customer support)
• Analyze marketing trends to understand who’s buying what and why.
• Satisfy regulations that require accurate record keeping and proof of customer consent.

The table below provides a breakdown of the main ways your PII is collected:

Collecting PII is just the first step. The real challenge begins once that information spreads across scattered databases, cloud applications, and backup drives throughout your organization.

Structured data, like CRM records, is relatively straightforward to manage. The risks lie in unstructured data such as emails, chat logs, scanned documents, and server logs, where personal details mingle with everyday business content.

Tracking, classifying, and securing these scattered pieces of information can strain even seasoned IT teams and turn compliance audits into time-consuming processes.

Challenges with Storage Infrastructure

Unstructured storage is when data is stored in a way that doesn’t follow a set data model or format. Structured databases contain data in clearly defined tables, while unstructured storage includes various types of files, such as emails, photos, videos, presentations, and other valuable documents.

Organizations face the following challenges because of the complexity of data storage:

• Data discovery. Unstructured storage is common, so it can be hard for businesses to identify PII. In 2024, 1 in 3 data breaches featured shadow data. This is data that is not stored or controlled by the IT team and is not part of the company’s centralized data management system.
• Risks to cloud security. In 2023, 82% of breaches involve data stored in the cloud, and 39% of events involve attacks on several environments, which cost an average of $4.75 million.
• The growth of shadow IT. If your official systems are slow or hard to use, your staff might use unapproved apps and services to hold PII data. This can create shadow IT environments that your IT team doesn’t see, which can cause critical data to be spread out across platforms.

Data Retention and Lifecycle Management

Locking PII behind encryption is only half the job. IT teams still have to decide precisely how long each data set lives and how to erase it everywhere once that timer expires.

Striking a balance between the needs of the business and the demands of legal and compliance requirements can be pretty challenging, especially when it comes to managing data retention and its lifecycle. This can lead to several obstacles that organizations should navigate carefully.

• Conflicting data retention rules. GDPR might demand a “right to be forgotten” in 30 days, while finance needs seven-year records for tax audits.
• Ghost copies and backups. Data you deleted can linger in nightly snapshots, DR replicas, and SaaS platforms that the company adopted without telling IT.
• Alert fatigue from stale accounts. Old user IDs with lingering PII keep triggering DLP alerts and access-review tickets, clogging your SOC queue and masking real threats.
• Automated purge failures. A single mistagged record can undo a bulk-delete job, leaving pockets of sensitive data behind and forcing manual cleanup.

A strong data retention program pairs policy (clear, department-approved timelines) with tooling such as data classification scanners, automated purge workflows, and periodic spot checks that prove the data is permanently deleted. This is how your IT team can proactively reduce breach exposure and avoid scrambling when regulatory authorities request evidence of compliance.

Meanwhile, data privacy regulations are also designed to minimize the amount of data you collect and limit retention periods to what’s strictly necessary. For example, GDPR states that organizations must only gather and retain personal data essential to their specific business purposes. Similarly, the CCPA requires businesses to explain their data retention periods in a way that aligns with their actual needs.

Here are a few key elements to consider in your data retention strategy:

• Schedule data retention. Set realistic timelines for how long different types of data need to be kept based on your operational requirements and any legal obligations.
• Dispose of data securely. Use methods like cryptographic erasure or physically destroying old storage media so expired data can’t come back to haunt you.
• Minimize data collection. Collect and keep only the personal information that is necessary for your business. This not only helps in compliance but also reduces your overall risk.

If you’re worried about sensitive data already floating around, consider a data leak detection solution like Digital Risk Protection. The platform is capable of detecting up to 90% of violations related to online brand abuse. It continuously monitors dark web forums, underground marketplaces, and data dumps to alert you whenever your organization’s PII or credentials appear in unauthorized locations.

How to Keep PII Safe?

The best ways to secure PII are to use layered security measures that include technical safeguards, administrative regulations, and constant monitoring. We’ll discuss more these best practices below.

Technical Security Measures

Strong encryption methods like SSL/TLS for data in transit and AES-256 for data at rest are a good start for keeping PII safe. Your security stack should also include identity-based access controls, real-time monitoring, and data leak detection.

Best Practices for Data Governance

PII can’t be protected by technology alone. You will also need clear rules, sufficient training, and governance structures that make sure everyone in your business knows their responsibilities when it comes to keeping sensitive data safe.

1. Build a data governance framework that everyone understands

Explain the rules for collecting, processing, storing, and exchanging PII in accordance with compliance rules and best practices.

• Clear data classification schemes with handling requirements based on sensitivity levels.
• Data discovery processes that include periodically reviewing and auditing environments for PII.
• Data retention and disposal policies are aligned with regulatory requirements and business needs.

2. Turn policies into everyday practice

Introduce comprehensive training programs to ensure employees understand their role in protecting PII.

• Regular cybersecurity training to educate every employee on the importance of how data is collected, stored, and used.
• Incident response procedures and escalation protocols for potential PII compromises.
• Clear accountability structures for data protection responsibilities across departments.

3. Strategies for Regulatory Compliance

According to the IAPP, over 137 countries will have enacted data privacy laws by 2024. Businesses must comply with updated and revised preexisting requirements such as GDPR, CCPA, PIPEDA, and LGPD. This legislative growth is expected to continue as more countries develop comprehensive laws regulating privacy and AI.

a. How to meet multi-jurisdictional requirements

• Chart where you operate, where your customers live, and which regulations apply to each data flow.
• Use a consent management platform that records every opt-in, opt-out, and preference change.
• Deploy cookie banners that explain why you collect data and how users can change their minds.

b. Treat compliance as a living program

• Schedule quarterly reviews to spot gaps in your data protection strategy.
• Leverage services such as security assessments, penetration tests, or vulnerability scanning to validate that your controls work.
• Build a checklist for vetting vendors to ensure supply chain security.

PII Data Breaches and Real-World Cases

In 2024, 1.35 billion individuals were affected by PII data breaches, more than triple the number in 2023. Below are a few major incidents that show how personal data can slip through the cracks and what it costs when it does.

National Public Data Breach

A background check firm, National Public Data, had its defenses breached by hackers, who walked away with 2.9 billion records. Those files, packed with Social Security numbers, names, phone numbers, and addresses for about 270 million individuals, quickly popped up for sale on dark web forums.

AT&T Snowflake Incident

The cyber espionage group UNC5537 found a weak spot in AT&T’s Snowflake cloud environment. They pulled down multiple troves of customer data and call logs, leaving AT&T scrambling to tighten security without disrupting everyday customer support.

Healthcare Email Server Hacks 

An email server breach at Kaiser Permanente exposed medical details of over 40,000 patients. This was followed by a separate attack against Summit Pathology, which compromised data for roughly 1.8 million patients. Both organizations had to launch extensive investigations, notify every affected patient, and show regulators that they were shoring up their defenses.

Group-IB’s Approach to Securing PII

Most breaches start with phishing emails, unpatched systems, misconfigured cloud buckets, or data leaked on forums you’ve never heard of. These familiar partners highlight the need for a proactive security posture with strategically aligned solutions that tackle all three problems at once:

• Spot your PII exposure early
• Block threats in real-time
• Respond fast when something inevitably slips through

Now, how do you turn that “see, block, and respond” approach into an everyday reality? At Group-IB, we take a unified approach to provide SOC teams with complete visibility so they can spend most of their time getting proactive and stopping threats before they occur.

Here’s a closer look at how each layer works:

1. Digital Risk Protection monitors open and dark web sources to detect stolen PII linked to your brand.
2. Threat Intelligence correlates breach dumps, botnet logs, and underground chatter to flag compromised logins and personal data tied to your domains. Linking threat intelligence with internal telemetry also gives your SOC a unified, continuous view of PII risk.
3. Attack Surface Management identifies potential sources of PII leaks through continuous monitoring of your external assets, while Managed XDR detects and prevents data exfiltration attempts.
4. Compromise Assessment detects previously unnoticed breaches.

This layered strategy improves detection of suspicious activities that might otherwise be missed with traditional, fragmented tools. And if a data leak does occur, our Incident Response retainer services puts pre-negotiated SLAs in motion immediately to contain PII exposure.

Ready to see your own risk profile through this lens? Get in touch with us today to explore how Group-IB’s unified stack keeps PII secure and improves your data breach prevention strategy.