Overview A London Accounting firm specialising in tax consulting and financial advisory, for UK and US/EMEA clients, faced a growing concern regarding cyber threats. With an increase
One of the most infamous real-world zero-day exploits is EternalBlue, a vulnerability discovered in Microsoft’s implementation of the Server Message Block (SMB) protocol. Here’s a detailed overview:
EternalBlue was a vulnerability in Microsoft’s SMBv1 protocol, used for file sharing and communication between devices on the same network. The exploit allowed an attacker to execute arbitrary code remotely without requiring authentication. By sending specially crafted packets to a vulnerable server, an attacker could gain full control over the system.
EternalBlue was not disclosed by security researchers or the company—it was leaked. The exploit was developed by the National Security Agency (NSA) as part of their cyber toolkit but was stolen and published online in 2017 by a hacking group called The Shadow Brokers.
Once leaked, hackers weaponised EternalBlue almost immediately. The exploit had several devastating consequences:
WannaCry Ransomware (2017)
EternalBlue was used as the backbone for the WannaCry ransomware attack, which encrypted files on infected systems and demanded payment in Bitcoin.
Impact: It infected over 200,000 systems across 150 countries, disrupting hospitals, banks, transportation systems, and businesses worldwide.
Notable victims: The UK’s National Health Service (NHS) faced significant outages, forcing hospitals to cancel surgeries and redirect emergency services.
NotPetya (2017)
A month after WannaCry, another global attack known as NotPetya exploited EternalBlue to spread rapidly. NotPetya was a destructive wiper disguised as ransomware, targeting Ukraine initially but causing billions of dollars in damages worldwide.
Impact: Companies like Maersk, Merck, and FedEx suffered catastrophic disruptions to their operations.
Other Campaigns
Multiple hacking groups continued to use EternalBlue for cryptocurrency mining campaigns, espionage, and network intrusions well into 2019, targeting systems that had not been patched.
Prevalence of Vulnerable Systems: At the time of the leak, millions of devices worldwide were running unpatched versions of Windows.
Self-Propagating Capability: EternalBlue could automatically spread from one vulnerable system to another, making it a potent tool for worms like WannaCry.
Critical Targets: The exploit hit systems crucial to infrastructure, healthcare, and commerce, revealing the vulnerability of legacy systems.
Patches Released: Microsoft released a patch for the vulnerability in March 2017, two months before the WannaCry attack. However, many systems were not updated in time.
• NSA Criticism: The NSA faced backlash for hoarding such a powerful exploit without informing Microsoft, which could have mitigated the risk earlier.
• Security Awareness: EternalBlue highlighted the dangers of unpatched systems and reliance on outdated software, prompting organizations to invest more in cybersecurity hygiene.
EternalBlue is a textbook example of how a zero-day exploit, when weaponized, can cause widespread chaos. Even years later, its ripple effects are felt, as it remains a tool in the arsenals of cybercriminals targeting unprotected systems.
