Heathrow Airport 2025 Cyberattack: What Happened and Why It Matters

In late September 2025, London’s Heathrow Airport was swept up in a major cyber incident that disrupted operations across Europe. Investigators later determined that the attackers hit Collins Aerospace’s cloud-based MUSE check-in system – a shared platform used by airlines at Heathrow and other major airports. The breach disabled electronic check-in kiosks, bag-drop machines and boarding systems, forcing staff to revert to manual processing. Hundreds of flights were delayed or canceled. For example, by Saturday Sept 20, 29 departures/arrivals were canceled at Heathrow, Berlin and Brussels (with hundreds more delayed). Heathrow Airport warned passengers of “possible disruptions” and urged travelers to check flight status with their airline before coming to the airport. The chaos rippled through the air travel network, with Brussels and Dublin airports also affected. Importantly, aviation safety and air-traffic control systems were not affected by the hack– the attack struck only passenger processing services.

Attack Vector – Ransomware on a Vendor’s System

By September 22, the EU’s cybersecurity agency (ENISA) and the UK’s NCSC had confirmed the root cause: ransomware on a third-party system. In a statement ENISA said it was “aware of the ongoing disruption” and that it was caused by a “third-party ransomware incident”. In practice, this means the attackers infiltrated Collins Aerospace’s MUSE network and encrypted or disabled its software and databases. Collins (owned by RTX) acknowledged a “cyber-related disruption” in MUSE at selected airports and said it was working urgently to restore service.

Technical details on the breach are still emerging. No specific malware family has been publicly named, nor has a ransom demand been released. Ransomware attacks typically start with stolen credentials or phishing, and then execute code that locks out the operators. Here the result was the same: automated check-in desks went dark. Security experts note that this was essentially a supply-chain attack on Heathrow’s supply network. As one analyst explained: “This wasn’t Heathrow’s own IT falling over, it was a supply-chain hit… By breaching the vendor, [the hackers] managed to hit Heathrow, Brussels, and Berlin all at once. It’s a back-door route that bypasses the airport’s own defenses” . Indeed, Collins’s MUSE system lets multiple airlines share desks and kiosks at an airport , so attacking it has cascading effects. The Belgian government and airport authorities later echoed this: even a single-vendor failure created a domino effect across schedules, passenger flows and crew availability . (To date no group has claimed responsibility, and reports say no extorted data or leak has surfaced ; investigators are still probing attribution.)

Timeline and Scope of the Breach

The hack appears to have been launched on the night of Friday Sept 19, 2025 and was detected quickly. By early Saturday Sept 20, Heathrow confirmed it was affected, and airlines reported that automated check-in and boarding systems were down. Airports immediately fell back on manual procedures. For example:

• Sept 19 (Friday evening): Collins Aerospace’s monitoring likely detected anomalous activity in MUSE (this was later confirmed by investigators).

• Sept 20 (Saturday): Major disruptions unfolded. Heathrow, Berlin and Brussels logged massive queues as staff checked people in manually. By Saturday morning, Heathrow’s data feeds showed hundreds of delays and at least 29 cancellations across those airports. Brussels Airport even cancelled half of its Sunday departures to manage backlogs.

• Sept 21 (Sunday): Some recovery began. Heathrow reported that most flights were moving (with only minor delays), and only a dozen or so flights had been scrubbed. Brussels and Dublin still had disruptions (Dublin kept operations but said passengers should confirm flights with airlines). Collins Aerospace and airport tech teams continued rolling out fixes.

• Sept 22 (Monday): By Monday many services were restored. Heathrow spokesman said work “continues to resolve and recover” from the outage, and that “the vast majority of flights have continued to operate”. ENISA publicly confirmed the cause as ransomware, and news reports indicated Collins was in “the final stages” of deploying software updates to restore its MUSE check-in platform. British and German authorities remained in contact with airports.

Authorities emphasized the attack was not ongoing indefinitely. EU sources said it was “not a widespread or severe attack” beyond the checked-in systems. By Monday most airports were managing, and airline passengers were able to rebook or use backup procedures. Heathrow continued advising travellers to verify flights and only arrive the recommended time before departure.

Systems and Services Affected

The ransomware primarily hit passenger-facing systems. Specifically, the ARINC Multi-User System Environment (Muse) platform – which manages check-in desks, kiosks, boarding gates and bag-drop machines shared among airlines – was shut down. In practical terms this meant:

• Self-service kiosks and airline check-in desks went offline, so agents had to process every customer by hand. Many passengers faced hours-long queues as staff printed boarding passes and tags manually. (One traveler likened the boarding process to the “early decades of commercial air travel,” complete with hand-written tickets.)

• Baggage drop machines and automatic tag printers were disabled, forcing airlines to hand-write luggage labels and queue luggage throughput.

• Boarding gates and flight displays that rely on MUSE data were affected, slowing down boarding.

• NOT affected: Air traffic control, flight routing and safety systems remained online as usual. The European Commission confirmed that core ATC and safety infrastructure were “unaffected” by the cyberattack. Fueling, security checks, runway operations and radar systems were all separate; only passenger processing was impacted. No passenger or airline data loss has been reported, suggesting the attack focused on availability rather than data theft.

Overall, the disruption centered on services like electronic check-in, boarding, and baggage processing. Heathrow, for instance, warned that the only impact was on those systems – everything else (flight operations, airside functions) was running normally. Even so, the effect was highly visible. Thousands of travelers were left in limbo, and airlines had to scramble to rebook and feed affected passengers.

Response by Heathrow and Authorities

Heathrow Airport and its airline tenants activated emergency protocols immediately. Heathrow brought in extra ground staff to assist at check-in areas and set up manual counters. As one notice put it: “While the provider works to resolve the problem quickly, we advise passengers to check their flight status... and arrive no earlier than [the advised time]. Additional colleagues are available in check-in areas to assist… We apologise for any inconvenience.”. Heathrow publicly thanked airlines for implementing contingency plans and emphasized that most flights were continuing to operate under the circumstances.

Airlines and airports went into crisis mode. Some, like Delta Air Lines, said they had minimal impact because of pre-planned workarounds. EasyJet reported normal operations by Saturday afternoon. Others (British Airways, Ryanair, etc.) offered passengers hotel accommodation and meals as needed for missed connections. Brussels Airport staff shifted to laptops and tablets to handle check-ins and even cancelled dozens of flights to clear queues. The Belgian operator warned it would continue manual procedures into Monday.

On the governmental side, the UK’s National Cyber Security Centre (NCSC) was immediately involved. The NCSC said it was “working with Collins Aerospace and affected UK airports, alongside the Department for Transport and law enforcement” to understand the incident. London’s Transport Minister (Heidi Alexander) said she was “receiving regular updates” on the situation. Similarly, German cyber authorities were liaising with Berlin’s airports. In Brussels, the European Commission treated it as a third-party IT outage, assuring the public there was “no evidence of a wider attack” and that core flight safety systems were secure. ENISA coordinated with national agencies to support the technical recovery.

In short, response efforts were multilayered: Heathrow and airlines managed the immediate passenger impact, Collins/RTX engineers focused on fixing the software, and government cyber teams monitored and offered guidance. The NCSC and EU officials urged all airports and airlines to use published cybersecurity guidance to bolster their resilience against such attacks.

Impact and Consequences

In the short term, the Heathrow breach caused significant disruption: hundreds of flights across Europe were delayed or canceled over that weekend. Many long-haul and short-haul services ran late, eroding passenger confidence. The logistical knock-on effect was severe – ground staff had to reallocate crews and resources on the fly, and baggage systems fell behind. Airports reported that ~85–90% of flights still got away, but many travelers endured extra long waits. The direct economic cost was hard to tally, but estimates (from past incidents) suggest on the order of tens of millions of dollars per day per major hub in lost revenue and additional staffing costs. Insurance markets also took note: experts pointed out that many cyber-insurance policies do not clearly cover losses from dependent third-party failures, sparking a review of contract wording for aggregate, cross-border incidents.

Longer-term consequences include a renewed focus on aviation cybersecurity. The incident became a case study in supply-chain risk. As one industry expert noted: “This attack is a prime example of the supply-chain risks facing the aviation industry… A single cyberattack on one vendor can quickly escalate into widespread disruptions across multiple airports. Regulators and airport operators will likely re-examine how much processing is centralized versus segregated. It may spur tighter standards for critical suppliers (as some have already urged) and more frequent compliance checks. Airlines and airports may also accelerate plans for offline backups and disaster drills – indeed, analysts warned that if carriers do not have viable manual backup processes, “this incident will not be the last”.

One under-appreciated effect is on data security: although there is no confirmed data theft so far, experts warn that attackers in a platform like MUSE could have copied passenger or staff information while they were inside the system. If true, such data would be “gold dust” for future phishing or extortion campaigns. This raises questions about long-term privacy impacts on passengers and the need for post-incident forensics.

For passengers, the immediate fallout was frustration and uncertainty. Many were stranded, missed connections, or had to rebook through alternate airports. Airlines had to arrange food, accommodations, and refunds en masse. Public confidence in check-in tech was shaken, although surveys show most people ultimately understood this was an industry-wide outage beyond Heathrow’s direct control. In the broader sense, the event sent a clear message: modern travel relies on interconnected IT, and those links are potential points of failure or attack.

Lessons and Recommendations

This incident underscores that even top-tier infrastructure can be blindsided by single points of failure in the supply chain. IT professionals and airport operators should take away several key lessons:

• Harden Third-Party Supply Chains. Perform rigorous security audits of all critical vendors (especially those managing passenger processing). Enforce strict security standards and regular penetration testing for supplier systems. (As one expert put it, “security can’t stop at your own network – every supplier must meet the same high standards”.)

• Network Segmentation & Isolation. Architect airport IT so that key services (check-in, baggage, flight ops) are compartmentalized. That way, if one system like MUSE is breached, it cannot directly compromise air-traffic control or communications. Consider read-only backups for essential databases and limit vendor system access to the minimum needed.

• Robust Fallback Procedures. Regularly drill manual check-in and baggage-check processes. Make sure staff know how to operate without computers (and that enough paper boarding passes and luggage tags are on hand). Heathrow’s experience showed that well-practiced contingencies and extra floor staff can greatly reduce chaosi. Airlines should also test switching to alternative ticketing platforms or interim procedures.

• Stronger Authentication and Updates. Enforce multi-factor authentication (MFA) and least-privilege access for all cloud and on-premises systems, including third-party portals. Keep critical software fully patched against known vulnerabilities. Collins Aerospace reportedly launched an urgent patch over the weekend; in the future, those patches should be pre-tested and ready for immediate deployment.

• Continuous Monitoring and Threat Hunting. Use advanced security tools to watch for anomalies not only on your own network but also on connected supplier networks. Log and audit third-party activity, and set up alerts if unusual patterns appear. In this case, quicker detection of the initial intrusion (e.g. by verifying the integrity of the MUSE servers) might have shortened the outage.

• Information Sharing and Coordination. Take advantage of industry and governmental resources (NCSC, ENISA, aviation sector CISA equivalents) to stay informed about emerging threats. Share threat intelligence promptly with partners and regulatory bodies. In a crisis, working closely with cybersecurity agencies (as the airports did) can speed up containment and recovery.

• Cyber Insurance and Contracts. Review your cyber insurance policies to ensure they cover losses from third-party outages and ransom events. Also update vendor contracts to include clear cyber-incident response obligations and liability for security lapses. The Heathrow attack revealed “aggregated loss” scenarios that traditional policies may not fully contemplate.

• Training and Communication. Train all relevant staff (from IT to front-line personnel) on incident response procedures. Practice communication plans so that management, regulators and customers are notified clearly. Heathrow’s early advisories (on X/Twitter and website) helped manage passenger expectations.

By implementing these measures, airports and airlines can reduce the chances of a similar disruption, or at least be better prepared to limit its scope. The 2025 Heathrow incident will likely be studied alongside past cases (like the 2024 Kyiv airport attack and various airline outages) as a warning: critical infrastructure is only as strong as its weakest link. Ensuring that every link in the chain is secure – and that robust backups exist when they fail – is now a top strategic priority for the aviation industry.

Sources: Authoritative news and agency reports, including Reuters and industry publications, as well as official statements from Heathrow Airport and the UK National Cyber Security Centre. These confirm the facts above about the incident’s cause, impact and response.