Ransomware is the fastest growing malware threat, targeting users of all types—from the home user to the corporate network. On average, more than 4,000 ransomware attacks have occurred daily since January 1, 2016. This is a 300 percent increase over the approximately 1,000 attacks per day seen in 2015. There are very effective prevention and response actions that can significantly mitigate the risk posed to your organization. Ransomware targets home users, businesses , and government networks and can lead to temporary or permanent loss of sensitive or proprietary information, disruption to regular operations, financial losses incurred to restore systems and files, and potential harm to an organization’s reputation. Protecting your networks
Ransomware is a form of malware that targets your critical data and systems for the purpose of extortion. Ransomware is frequently delivered through spear phishing emails
Mohammed Abul Kalam, PhD
Ransomware is the fastest growing malware threat, targeting users of all typesfrom the home user to the corporate network. On average, more than 4,000 ransomware attacks have occurred daily since January 1, 2016. This is a 300 percent increase over the approximately 1,000 attacks per day seen in 2015. There are very effective prevention and response actions that can significantly mitigate the risk posed to your organization. Ransomware targets home users, businesses , and government networks and can lead to temporary or permanent loss of sensitive or proprietary information, disruption to regular operations, financial losses incurred to restore systems and files, and potential harm to an organizations reputation.
Ransomware may direct a user to click on a link to pay a ransom; however, the link may be malicious and could lead to additional malware infections. Some ransomware variants - display intimidating messages, such as: Your computer was used to visit websites with illegal content. To unlock your computer, you must pay a $100 fine. You only have 96 hours to submit the payment. If you do not send money within provided time, all your files will be permanently encrypted and no one will be able to recover them.
What is Ransomware? Ransomware is a form of malware that targets your critical data and systems for the purpose of extortion. Ransomware is frequently delivered through spear phishing emails. After the user has been locked out of the data or system, the cyber actor demands a ransom payment. After receiving payment, the cyber actor will purportedly provide an avenue to the victim to regain access to the system or data. Recent iterations target enterprise end users, making awareness and training a critical preventive measure.
Protecting Your Networks Educate Your Personnel: Attackers often enter the organization by tricking a user to disclose a password or click on a Virus-laden email attachment. Remind employees to never click unsolicited links or open unsolicited attachments in emails. To improve workforce awareness, the internal security team may test the training of an organizations workforce with simulated phishing emails
Proactive Prevention is the Best Defense: Prevention is the most effective defense against ransomware and it is critical to take precautions for protection. Infections can be devastating to an individual or organization, and recovery may be a difficult process requiring the services of a reputable data recovery specialist.
We may recommend that users and administrators take the following preventive measures to protect their computer networks from falling victim to a ransomware infection: Preventive Measures: (1) implement an awareness and training program. Because end users are targets, employees and individuals should be aware of the threat of ransomware and how it is delivered (2) enable strong spam filters to prevent phishing emails from reaching the end users and authenticate inbound email using technologies like Sender Policy Framework (SPF), Domain Message Authentication Reporting and Conformance (DMARC), and Domain Keys Identified Mail (DKIM) to prevent email spoofing (3) scan all incoming and outgoing emails to detect threats and filter executable files from reaching end users (3) configure firewalls to block access to known malicious IP addresses (4) Patch operating systems, software, and firmware on devices. Consider using a centralized patch management system (5) set anti-virus and anti-malware programs to conduct regular scans automatically (6) manage the use of privileged accounts based on the principle of least privilege: no users should be assigned administrative access unless absolutely needed; and those with a need for administrator accounts should only use them when necessary. For additional information on Avoiding Social Engineering and Phishing Attack Configure access controlsincluding file, directory, and network share permissionswith least privilege in mind. If a user only needs to read specific files, the user should not have write access to those files, directories, or shares (7) disable macro scripts from office files transmitted via email. Consider using Office Viewer software to open Microsoft Office files transmitted via email instead of full office suite applications (8) implement Software Restriction Policies (SRP) or other controls to prevent programs from executing from common ransomware locations, such as temporary folders supporting popular Internet browsers or compression/decompression programs, including the AppData/LocalAppData folder (9) consider disabling Remote Desktop protocol (RDP) if it is not being used (10) use application whitelisting, which only allows systems to execute programs known and permitted by security policy (11) execute operating system environments or specific programs in a virtualized environment, and (12) categorize data based on organizational value and implement physical and logical separation of networks and data for different organizational units.
Business Continuity Considerations: (1) backup data regularly. Verify the integrity of those backups and test the restoration process to ensure it is working (2) conduct an annual penetration test and vulnerability assessment (3) secure your backups. Ensure backups are not connected permanently to the computers and networks they are backing up. Examples are securing backups in the cloud or physically storing backups offline. Some instances of ransomware have the capability to lock cloud-based backups when systems continuously backup in real time, also known as persistent synchronization. Backups are critical in ransomware recovery and response; if you are infected, a backup may be the best way to recover your critical data.
What to do if infected with Ransomware should preventive measures fail? We recommend that organizations consider taking the following steps upon an infection with ransomware: (1) isolate the infected computer immediately. Infected systems should be removed from the network as soon as possible to prevent ransomware from attacking network or share drives, and (2) isolate or power-off affected devices that have not yet been completely corrupted. This may afford more time to clean and recover data, contain damage, and prevent worsening conditions.
Protect Your Networks from Ransomware: (1) immediately secure backup data or systems by taking them offline. Ensure backups are free of malware (2) contact law enforcement immediately. We strongly encourage you to contact law enforcement immediately upon discovery to report a ransomware event and request assistance (3) if available, collect and secure partial portions of the ransomed data that might exist, and (4) if possible, change all online account passwords and network passwords after removing the system from the network. Furthermore, change all system passwords once the malware is removed from the system.
Delete Registry values and files to stop the program from loading. Implement your security incident response and business continuity plan. Ideally, organizations will ensure they have appropriate backups, so their response to an attack will simply be to restore the data from a known clean backup. Having a data backup can eliminate the need to pay a ransom to recover data. There are serious risks to consider before paying the ransom. We do not encourage paying a ransom to criminal actors. However, after systems have been compromised, whether to pay a ransom is a serious decision, requiring the evaluation of all options to protect shareholders, employees, and customers. Victims will want to evaluate the technical feasibility, timeliness, and cost of restarting systems from backup. Ransomware victims may also wish to consider the following factors: (1) paying a ransom does not guarantee an organization will regain access to their data; in fact, some individuals or organizations were never provided with decryption keys after paying a ransom (2) some victims who paid the demand were targeted again by cyber actors (3) After paying the originally demanded ransom, some victims were asked to pay more to get the promised decryption key, and (4) paying could inadvertently encourage this criminal business model.
How Law Enforcement Can Help? Any entity infected with ransomware should contact law enforcement immediately. Law enforcement may be able to use legal authorities and tools that are unavailable to most organizations. Law enforcement agency can enlist the assistance of international law enforcement partners to locate the stolen or encrypted data or identify the perpetrator. These tools and relationships can greatly increase the odds of successfully apprehending the criminal, thereby preventing future losses. Our law enforcement places a priority on conducting cyber investigations in a manner that causes minor disruption to a victim entitys normal operations and seeks to work cooperatively and discreetly with that entity. Our law enforcement agencies use investigative measures that avoid unnecessary downtime or displacement of a companys employees. The country law enforcement closely coordinates its activities with the affected organization to avoid unwarranted disclosure of information.
Links to Other Types of Malware: Systems infected with ransomware are also often infected with other malware. In the case of CryptoLocker, a user typically was infected by opening a malicious attachment from an email. This malicious attachment contained Upatre, a downloader, which infected the user with GameOver Zeus. GameOver Zeus was a variant of the Zeus Trojan used to steal banking information and other types of data. After a system became infected with GameOver Zeus, Upatre would also download CryptoLocker. Finally, CryptoLocker encrypted files on the infected system and demanded a ransom payment.
The disruption operation against the GameOver Zeus botnet also affected CryptoLocker, demonstrating the close ties between ransomware and other types of malware. In June 2014, an international law enforcement operation successfully weakened the infrastructure of both GameOverZeus and CryptoLocker.
The writer is Former Head, Department of Medical Sociology, Institute of Epidemiology, Disease Control Research (IEDCR), Dhaka, Bangladesh, E-mail: [email protected]
