This article is linked to a series of articles about different types of Cyber Attacks. They can be viewed in the Information/Cyber Security News section of the Data Protection Education website or as part of the Information & Cyber Security Best Practice Area. Each article discusses a different type of cyber attack, steps to try to minimise the risk and guidance
Credential stuffing takes advantage of people reusing username and password combinations across different accounts.
Attackers fraudulently obtain valid combinations for one site and then use them across other sites to try and gain access to accounts. Any website that requires an online login is potentially vulnerable.
Many people re-use the same username/email password combination, when those credentials are exposed (by a database breach or phishing attack) submitting those sets of stolen credentials into many sites can allow an attacker to compromise those accounts too.
Credential stuffing is a type of brute force attack. Brute forcing will try multiple passwords against one or many accounts, guessing passwords. Credential stuffing will use specifically breached username/password pairs against other websites. It is one of the most common techniques to access user accounts because it is easy for the hacker to do and does not require any specialist skills.
Steps of an Attack
- The attacker acquires usernames and passwords from a website breach, phishing attack or password dump site.
- The attacker uses automated tools to test the stolen credentials against many websites (for instance, social media sites, online marketplaces or web apps).
- If the login is successful, the attacker knows they have a set of valid credentials.
Now the attacker knows they have access to an account. Potential next steps include:
- Draining stolen accounts of stored value or making purchases.
- Accessing sensitive information such as credit card numbers, private messages, pictures, or documents.
- Using the account to send phishing messages or spam.
- Selling known-valid credentials to one or more of the compromised sites for other attackers to use.
A most recent credential stuffing attack reported by Computing on PayPayl account users:
PayPal has reset passwords on all impacted accounts
Defence against Credential Stuffing
- Use multi-factor authentication
- Use secondary passwords, PINS and security questions
- Use CAPTCHA
- IP Address block listing
- Biometrics
- Check against leaked passwords using the site: haveibeenpawned
- Notify staff about unusual security events
What to do in the event of a cyber attack
First, follow your cyber response plan. Record the incident in your internal incident log, inform your governing board or trustees, and contact your Data Protection Officer (DPO) as soon as possible if personal data could be involved.
Incidents or attacks where a security breach may have taken place, or other damage was caused, should also be reported to an external body. The SLT digital lead is responsible for assigning someone to report any suspicious cyber incidents or attacks. This person will need to report to:
- Report Fraud, which replaced Action Fraud in December 2025, on 0300 123 2040 or through the Report Fraud website. Make sure it is recorded as a crime report so that you receive a crime reference number.
- the DfE sector cyber team at
This email address is being protected from spambots. You need JavaScript enabled to view it.
You may also need to report to:
- the National Cyber Security Centre (NCSC) if the incident or attack causes long-term school closure, the closure of more than one school, or serious financial damage. If you're not sure who to report to, use the government's cyber incident signposting service.
- the Information Commissioner's Office (ICO) within 72 hours of becoming aware of a personal data breach, unless the breach is unlikely to result in a risk to people's rights and freedoms. If the risk is high, you must also tell the people affected without undue delay. Your DPO can help you assess this. We will do this on behalf of DPE customers.
- the Risk Protection Arrangement (RPA) emergency assistance helpline on 0800 368 6378 or
This email address is being protected from spambots. You need JavaScript enabled to view it. , if you are an RPA member, or your cyber insurance provider if you have one - your local police force if you suspect a safeguarding impact
- any third-party service providers whose systems are affected, so they can be part of a coordinated response
- Jisc CSIRT, if you are part of a further education institution.
You must act in accordance with:
- Report Fraud's guide to reporting cyber crime and fraud
- Academy Trust Handbook Part 6, if you are part of an academy trust. Since September 2025, academy trusts must not pay any cyber ransom demands.
- the ICO's guidance on personal data breaches.
Preserve the evidence
Police investigations may find out whether any compromised data has been published or sold, and identify the perpetrator. Preserving evidence is as important as recovering from the crime. Keep a clear record of what happened, when, and what actions you took. The DfE's guidance on record keeping in an incident explains what to capture.
Reporting suspicious emails and texts
Forward suspicious emails to