CryptoLocker was one of the most damaging ransomware attacks in history, encrypting files on infected computers and demanding ransom payments in bitcoin to decrypt them. At its peak in late 2013 and early 2014, CryptoLocker infected over 250,000 computers across the globe. However, a law enforcement operation in May 2014 took down the Gameover Zeus botnet which distributed CryptoLocker, effectively stopping the spread of the attack. So is CryptoLocker still active today in 2023? Here is a quick overview of the history and current status of CryptoLocker.
What was CryptoLocker?
CryptoLocker was a type of ransomware, a form of malware that encrypts files on a victim’s computer and demands payment in order to decrypt them. It was first detected in September 2013 and quickly spread via email attachments and infected websites. The ransomware used public and private key cryptography to encrypt files, leaving victims with no way to recover their data without the decryption key.
The ransom amount demanded was typically between $200-$400, paid in the cryptocurrency bitcoin to remain anonymous. If the ransom was not paid within 3 days, the ransom doubled. After 7 days, the encrypted data would become permanently inaccessible. CryptoLocker mainly targeted Windows computers, encrypting a wide range of important files like documents, photos, videos, and more.
How did CryptoLocker spread?
CryptoLocker was spread through exploit kits on compromised websites and phishing emails with malicious attachments. The emails pretended to be delivery notifications, voicemails, or other files to convince victims to open them. If opened, the CryptoLocker malware would install itself and begin encrypting files in the background while showing no outward symptoms.
The main malware network used to distribute CryptoLocker was the Gameover Zeus botnet. This botnet of over 500,000 infected computers could send out millions of phishing emails containing CryptoLocker on command. At its peak, CryptoLocker managed to infect over 250,000 computers in just 6 weeks.
Who was affected by CryptoLocker?
CryptoLocker infections were geographically widespread, with the most affected countries being the U.S., U.K., and Australia. But no region was safe from potential infection through phishing emails and web exploits.
The ransomware targeted individuals, businesses, government agencies, schools, hospitals – any Windows computer user with important or valuable files stored locally. Businesses were especially impacted since infections could spread quickly on company networks.
According to the U.K.’s National Crime Agency, CryptoLocker cost businesses a minimum of $27 million in ransom payments in just its first few months. The total extorted by the end of 2013 was estimated to be as high as $3 million.
What steps were taken against CryptoLocker?
CryptoLocker rose to prominence quickly and became very difficult to combat due to it’s decentralized command structure. But IT security researchers and law enforcement agencies did make some key breakthroughs in taking down CryptoLocker:
- Researchers discovered flaws in CryptoLocker’s implementation of encryption and developed tools to recover some encrypted files without paying ransom.
- Internet service providers began blocking potential phishing domains used to spread CryptoLocker.
- In May 2014, the Operation Tovar international task force took down the Gameover Zeus botnet.
- In June 2014, the U.S. Department of Justice charged a Russian hacker Evgeniy Bogachev as the mastermind behind CryptoLocker. He remains at large with a $3 million bounty.
These efforts ultimately led to CryptoLocker infections being almost completely halted by the end of 2014, nearly a year after it initially appeared.
Is CryptoLocker still active today?
No, the original CryptoLocker botnet is no longer active or spreading new infections today in 2023. Key factors that led to its demise include:
Gameover Zeus botnet takedown
The primary distribution network spreading CryptoLocker was taken down in Operation Tovar in May 2014. With Gameover Zeus dismantled, CryptoLocker lost its botnet army to send out new malicious emails.
Decentralized infrastructure
CryptoLocker had no central command server. It relied on bots communicating peer-to-peer, making the botnet harder to take down. But this also meant CryptoLocker couldn’t recover once most bots were removed from the network.
Expiration of encryption keys
CryptoLocker was programmed to create new encryption keys every few days. Old keys would expire automatically. This made recovering files without paying almost impossible after a few days. But it also meant infections became inert after active bots stopped updating keys.
So with no bots left in the Gameover Zeus network to generate new ransomware keys after May 2014, any remaining CryptoLocker infections could no longer encrypt new files or even maintain existing encryptions.
Creator remains at large
The accused creator of CryptoLocker, Evgeniy Bogachev, remains at large despite a $3 million bounty. So the mastermind behind CryptoLocker cannot reestablish control of the botnet infrastructure to revive the attack.
Could CryptoLocker make a comeback?
While extremely unlikely, some security experts warn that CryptoLocker could potentially return if factors aligned in its favor again:
- Bogachev could rebuild botnet infrastructure to distribute CryptoLocker if not captured.
- The CryptoLocker code or encryption keys may still be available on cybercrime forums for malicious reuse.
- Low prosecution rates could motivate other ransomware developers to try a similar model.
However, most consider these risks minimal. CryptoLocker relied heavily on Gameover Zeus which has been dismantled. Modern security is also better equipped to detect and block such threats. The crypto payment ecosystem has changed considerably too since 2014.
Overall, the consensus is that while ransomware remains a serious threat, the original CryptoLocker botnet is long dead and extremely unlikely to return in its original form.
CryptoLocker legacy and lasting impact
While no longer active, CryptoLocker cemented ransomware as a lucrative criminal enterprise. It had a lasting impact that still shapes cybersecurity today:
Proved ransomware profitability
CryptoLocker raked in millions in ransom payments, proving ransomware could be highly profitable for cybercriminals. This motivated the rise of countless other ransomware strains in subsequent years.
Established ransomware best practices
CryptoLocker introduced now-standard ransomware practices like encryption of files, ransom deadlines, and demanding untraceable cryptocurrency payments. These tactics are still followed by most ransomware today.
Drove upgrades to cyberdefense
The CryptoLocker epidemic highlighted gaps in cybersecurity against malware and phishing. This drove government and industry efforts to improve email filtering, endpoint security, and user awareness education.
Ransomware continues adapting
CryptoLocker also demonstrated the ability for ransomware developers to rapidly innovate new techniques and evade defenses. Modern ransomware families like REvil and Ryuk continue advancing encryption, distribution, and monetization methods.
So while CryptoLocker itself is dead, its legacy lives on as ransomware remains a billion dollar criminal enterprise impacting businesses across the globe years later.
Conclusion
CryptoLocker was one of the most devastating cyberattacks of its time when active in late 2013 and early 2014. But fortunately, a coordinated global law enforcement effort succeeded in dismantling the Gameover Zeus botnet that spread CryptoLocker, effectively stopping infections within a year.
Today in 2023, nearly a decade later, the original CryptoLocker botnet is long inactive and considered dead. However, the criminal innovation of CryptoLocker firmly established ransomware as a lucrative enterprise for cybercriminals. Ransomware remains a major threat with new families like Ryuk constantly emerging. But CryptoLocker itself is highly unlikely to return in its original form and scope.
While cybersecurity has improved considerably since 2014, CryptoLocker serves as an important case study in how quickly ransomware can emerge and inflict massive damage globally. Its demise also demonstrated how law enforcement collaboration can successfully combat ransomware networks. But organisations must continue strengthening defenses and staff awareness as ransomware continues evolving in sophistication.
