What Is A Tailgating Attack In Cybersecurity?

A tailgating attack is when someone who is not supposed to be in an area gets in by following really close to someone who is allowed to be there. This kind of attack usually starts at a door or a secure building. It can cause big problems with cybersecurity if the person gets to computers, servers or important papers.

When people who are in charge of security think about how someone might break in they usually think about people who are trying to get in from away or people who are sending fake emails to try to trick others. But if someone can get into a building they can cause as many problems: they can get into the network, see private information, break rules and mess up the whole system.

According to research, social engineering attacks are becoming increasingly frequent, with 989,000 unique phishing attacks detected worldwide in 2024. And tailgating attacks work because they use the same tricks that make those fake emails work.

This guide is going to explain what tailgating attacks are, why they are a problem, for cybersecurity and what companies can do to stop people from getting in when they are not supposed to.

Key Takeaways

Tailgating is a physical social engineering attack where an unauthorized person follows an authorized user into a restricted area.
Although it begins as a physical access issue, tailgating can lead to cybersecurity incidents if attackers reach systems, servers, or sensitive data.
Tailgating, phishing, spoofing, and business email compromise all exploit trust, urgency, or weak verification processes.
Organizations should combine employee training, visitor controls, access monitoring, and incident reporting to reduce risk.
Email authentication protocols such as DMARC, SPF, and DKIM help reduce email-based impersonation, complementing broader social engineering defenses.

This guide is going to explain what tailgating attacks are, why they are a problem, for cybersecurity and what companies can do to stop people from getting in when they are not supposed to.

What Is Tailgating in Cybersecurity?

A tailgating attack in cybersecurity is when someone who is not supposed to be gets into a secure area or system by walking in behind someone who is allowed to be there. This person will often wear clothes that make them look like they belong so nobody notices them. They can get into places like server rooms or other areas with computers and data.

For example, someone who wants to cause trouble might dress up like a technician and wait by the door to the server room at a company. When an employee who is allowed in the room uses their badge to open the door the troublemaker will quickly walk in behind them. They do not need to use a badge or password to get in. Once they are inside they can plug an USB drive into a computer, put keyloggers on the system or look at secret information.

Even though this person is not breaking into the system using a computer they can still cause problems for the companys cybersecurity. The tailgating attack is a thing but it can still hurt the companys computers and data. The person who gets in can do a lot of damage even if they are not very good at using computers. The company’s cybersecurity is at risk when someone gets into the building who is not supposed to be.

Tailgating vs. Piggybacking: What’s the Difference?

Though often used interchangeably, tailgating and piggybacking have a meaningful distinction in cybersecurity contexts:

Tailgating: The unauthorized person enters without the knowledge or consent of the authorized person. For instance, sneaking in close behind someone as the door is closing.
Piggybacking: The unauthorized person is allowed in with the consent of the authorized individual, often due to misplaced trust or social pressure. For example, someone asks to be let in, and the authorized person agrees.

TL;DR: Tailgating vs. Piggybacking

Factor	Tailgating	Piggybacking
Authorized user awareness	Unaware	Aware
Consent given	No	Yes (misguidedly)
Example scenario	Slipping through a closing door unnoticed	Asking an employee to hold the door open
Primary exploit	Inattention	Social pressure / politeness
Prevention control	Mantraps, turnstiles, badge-only access	Credential verification training, escort policies

How Tailgating Connects to Email Security

Tailgating and phishing rely on the same core weakness: misplaced trust. In a physical setting, an attacker may follow an employee through a secure door. In email, an attacker may impersonate a trusted domain, executive, vendor, or service provider to bypass human suspicion.

This is where domain-level controls become essential. DMARC, SPF, and DKIM help verify whether an email is legitimately authorized to send on behalf of your domain, reducing the risk of email spoofing, phishing, and business email compromise. PowerDMARC gives security teams a centralized view of authentication failures, unauthorized sending sources, and domain spoofing attempts so they can respond quickly and maintain control.

How Do Tailgating Attacks Work?

Tailgating attacks follow a recognizable sequence. Understanding each step helps organizations identify and close the gaps attackers exploit:

Reconnaissance: The first thing the attackers do is called reconnaissance. This is when the attacker looks at the organization they want to attack and they try to figure out how to get in. They look for ways in. They watch what the employees do every day like when they come and go and what they wear. The attackers can get this information from things like media or from watching the organization in person or from doing research.
Preparation: The attacker decides what they will pretend to be like a technician or a delivery person or a contractor. They pick a door where a lot of people are walking in and out and where nobody is really paying attention.
Approach and social cuing: The attacker then tries to blend with the employees. They time it so they walk in when an employee is walking in and they might carry some boxes or look busy so nobody thinks it is weird.
Entry: The attacker follows the authorized person through the secured door before it closes, slipping into the restricted area without ever using their own credentials.
Post-entry exploitation: After the attacker gets into the building they might do things like use a computer that nobody is watching or plug in an USB stick or take pictures of sensitive information or look at what is on the screens and try to get passwords or install a keylogger.
Exfiltration or lateral movement: Finally the attacker might leave the building with the information they got. They might use the information they got to launch a digital attack like phishing or they might try to get into the organizations network once they are back, outside the building.

Why Tailgating Is a Cybersecurity Risk

Physical access and cybersecurity are not separate problems. When an unauthorized person gains entry to a secure area, the downstream digital consequences can be severe:

Unauthorized workstation access: An intruder can access open sessions, copy sensitive files, or install malicious software on unlocked devices.
Server room compromise: Physical access to network hardware enables traffic interception, device manipulation, or the introduction of rogue network access points.
Malware installation via removable media: A USB drive inserted into a networked computer can deploy ransomware, keyloggers, or data-exfiltration tools within seconds.
Credential theft: Visible passwords on sticky notes, printed access credentials, or unlocked password managers give attackers the keys to broader network access.
Compliance exposure: A physical breach in regulated industries like healthcare (HIPAA), finance (PCI DSS), or the public sector can trigger mandatory breach notification, audit findings, and significant financial penalties.
Follow-on phishing and spoofing: Information gathered during a physical intrusion, employee names, internal processes, system layouts, can be weaponized in targeted phishing campaigns, email spoofing, or business email compromise attacks after the intruder has left the building.
Reputational damage: A confirmed physical security breach, especially one that leads to data theft, erodes customer and partner trust in ways that are difficult and costly to repair.

Common Tailgating Methods and Warning Signs

A standard method of tailgating attacks is to impersonate an employee with similar clothing or appearance, such as wearing a uniform or carrying a backpack identical to those used by employees, and then following them through the door.

Other common methods include:

Method	What It Looks Like in Practice
Uniform or badge impersonation	Wearing similar clothing to staff, or a fake ID badge with matching logos and markings. Attackers may even claim someone else's badge number if questioned by security.
Delivery or contractor cover story	Posing as a courier, technician, or contractor with a plausible on-site reason, then asking an employee to hold the door.
Forgotten badge excuse	Claiming a forgotten access badge and asking to be let in. Most people comply rather than risk seeming unhelpful.
Stolen or purchased credentials	Using another person's stolen badge, or credentials bought from identity-theft marketplaces, to pass as authorized.
Timing exploitation	Entering during shift changes, lunch hours, or company events, whenever security scrutiny naturally drops.
Distraction tactics	Dropping items near a secured door or engaging someone in conversation to create a moment to slip through.
Unattended workstation follow-through	Once inside, locating a workstation an employee left unlocked while briefly away, enough time to copy files, install malware, or capture credentials.
Coworking or multi-tenant exploitation	In shared office buildings, following a visitor headed to a different tenant's floor, exploiting the lack of tenant-specific access controls.

How to Detect Tailgating Attempts

Detection is the first line of defense. Train employees and security personnel to recognize these behavioral and physical warning signs:

Individuals present in secure areas without a visible, valid badge.
People loitering near secured doors without a clear purpose.
Repeated requests to hold doors open, especially from unfamiliar individuals.
Individuals who avoid the reception desk or visitor sign-in process.
Mismatched uniforms, credentials, or identification that do not match standard organizational formats.
Access logs showing multiple entries attributed to a single badge swipe within a short time window.
Surveillance footage showing two or more individuals passing through a single badge-authenticated door entry.
Anti-passback system alerts indicate a badge was used for entry but not exit, or the other way around, breaking the expected sequence.

How to Prevent Tailgating Attacks

Reducing tailgating risk requires coordination between facilities, IT, security, HR, and end users. Effective prevention requires both physical and digital controls working together. Use the following checklist to assign controls and improve accountability.

Control	How It Helps	Owner
Badge verification	Ensures only authorized users enter restricted areas	Facilities / Security
Employee awareness training	Reduces social pressure and improves reporting confidence	Security / HR
Visitor management and escort policy	Limits access for contractors, guests, and vendors	Facilities
Surveillance and access log review	Enables detection, investigation, and evidence capture	Security / IT
Incident reporting channels	Gives employees a safe, clear path to report suspicious behavior	HR / Security
Email authentication (DMARC, SPF, DKIM)	Reduces domain spoofing and impersonation in related social engineering attacks	IT / Security
Periodic security audits and drills	Identifies gaps in physical controls before attackers do	Security / Management

Who Is Most at Risk for Tailgating Attacks?

Any organization with secured physical spaces is a potential target, but certain environments face elevated exposure:
Tailgating

Data centers sit at the top of the list simply because of what’s inside them: high-value hardware and direct network access make them a priority target. Mantraps and anti-tailgating sensors are the right call here, since these facilities can’t afford even one unnoticed entry.

Healthcare facilities face a different kind of risk. High foot traffic and HIPAA-regulated data mean there are more people moving through more entry points, which gives an attacker more opportunities to blend in. Visitor management and consistent staff training matter more here than hard physical barriers.

Financial institutions carry PCI DSS compliance requirements alongside genuinely high-value data, which makes them an attractive target on two fronts, regulatory and financial. Access log monitoring paired with CCTV analytics gives security teams the audit trail they need if something goes wrong.

Coworking spaces have a structural weakness built in: mixed tenants sharing common access points, with little to no tenant-specific control over who’s coming and going. Per-tenant badge zones and tighter reception screening close that gap.

Government facilities deal with the highest stakes, national security and classified data exposure, so the response has to match: multi-factor physical authentication and dedicated security personnel, not just badge readers.

Universities and campuses are the odd one out. Their open culture and constant flow of visitors work against tight physical security, even though valuable research data is often sitting just behind the next door. Awareness campaigns and stricter access controls specifically around server rooms tend to do more good here than blanket lockdowns.

What to Do If You Suspect a Tailgating Incident

If an employee or security staff member suspects unauthorized physical access has occurred, follow this response checklist:

Do not confront aggressively: Avoid direct confrontation with the suspected intruder to prevent escalation or physical risk.
Notify security or a manager immediately: Report the time, location, and description of the individual using your organization’s established reporting channel.
Record details: Note the exact time, access point, physical description, and any items the individual was carrying.
Review access logs and badge records: Identify which badge was used at the entry point and whether the log shows single versus multiple entries per swipe.
Review surveillance footage: Pull camera recordings from the relevant entry point and surrounding areas to confirm whether unauthorized entry occurred.
Verify whether systems or rooms were accessed: Check workstations for signs of tampering, unauthorized logins, or connected devices.
Reset affected credentials if needed: If a workstation was accessed or credentials may have been compromised, revoke and reset passwords and access tokens immediately.
Document the event for policy review: Record the full incident in writing and use it as input for a security policy or training update.

Conclusion: Reducing Tailgating Risk

Tailgating shows how fast misplaced trust turns into a security risk. What starts at a door can end with compromised servers, stolen credentials, and data exposure serious enough to trigger regulatory investigations. Physical and digital security aren’t separate problems, protecting one without the other still leaves you exposed.

The same logic applies to email. Spoofed domains, forged senders, and phishing messages exploit that same human suspicion gap when authentication controls are weak. If you’re training employees to question a stranger at the door, your email domain deserves the same scrutiny.

PowerDMARC helps organizations gain visibility and control over email authentication across DMARC, SPF, DKIM, BIMI, MTA-STS, and TLS-RPT. With centralized reporting, fast issue detection, and responsive global support, security teams can reduce spoofing risk, improve deliverability, and maintain compliance without unnecessary complexity.

Start your 15-day trial to see how PowerDMARC gives you clearer control over your domain security.

Frequently Asked Questions

What is an example of tailgating in cybersecurity?

A common example is an attacker dressed as a technician who waits near the entrance of a server room. When an authorized employee badges through, the attacker slips in behind them. Once inside, they may plug a malicious USB device into a networked computer or photograph sensitive credentials.

What is the difference between tailgating and piggybacking in cybersecurity?

Tailgating happens without the authorized person’s knowledge, the attacker just follows through a door unnoticed. Piggybacking is when the authorized person knowingly, if misguidedly, lets someone else in. Both end in unauthorized physical access, but piggybacking plays on politeness or social pressure rather than inattention.

How does tailgating work in cybersecurity?

A tailgating attack unfolds in stages: the attacker researches the target, selects a disguise or cover story, times their approach to coincide with an authorized entry, follows the authorized person through the secured door, and then exploits their physical access to compromise systems, steal data, or install malicious tools.

Is tailgating a cyberattack or a physical security attack?

Tailgating is a physical social engineering attack, but it frequently leads to cybersecurity incidents. Once the intruder reaches workstations, servers, or network access points, the physical breach becomes a digital one, with consequences that can include data theft, malware installation, compliance violations, and follow-on phishing or spoofing campaigns.

Can tailgating lead to phishing or email compromise?

Yes. Physical access can help attackers gather employee names, internal processes, device access, or credentials that may later be used in targeted phishing, domain spoofing, or business email compromise campaigns. This is why organizations in regulated industries should treat physical and email security as complementary, not separate, concerns.

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Ahona Rudra

Domain & Email Security Expert at PowerDMARC

Ahona is the Marketing Manager at PowerDMARC, with 5+ years of experience in writing about cybersecurity topics, specializing in domain and email security. Ahona holds a post-graduation degree in Journalism and Communications, solidifying her career in the security sector since 2019.

What Is a Tailgating Attack in Cybersecurity?