Ransomware is not new; however, cybercriminals have been using the malicious software with increased frequency in recent months as a sure fire way of generating income. It is now essential to protect networks from ransomware due to the increased risk of attack.
What Is Ransomware?
Ransomware can be considered to be rogue security software. It uses the same encryption that companies are advised to use to protect their data from cyberattackers. It encrypts files to prevent them from being used or accessed. Encrypted files can only be unlocked with a security key. Attackers lock data and demand a ransom to provide the security key. Without the key, the files will remain locked forever. It is therefore important for organizations to take steps to protect networks from ransomware. The threat of attack is increasing and failure to take proactive steps to reduce risk could prove costly.
Why are Ransomware Infections Increasing?
Malware can be used to record keystrokes and gain login credentials to access bank accounts, or to create botnets that can be sold as a service. Corporate secrets can be sold to the highest bidder, or Social Security numbers, names, and dates of birth stolen and sold on to identity thieves. However, attacks of this nature take time and effort. Ransomware on the other hand gives criminals the opportunity to make a quick buck. Several hundred of them in fact.
If a cybercriminal can infect a single machine with ransomware and lock that device, a ransom of between $300 to $500 can be demanded. The ransom must be paid using the virtually anonymous Bitcoin currency. Bitcoin can be bought, sold, traded, and spent without having to disclose any identifying information. Cybercriminals are able to demand ransoms with reasonable certainty that they will not be caught.
Ransomware-as-a-service is being offered on underground networks, meaning cybercriminals do not need to be skilled hackers or programmers. For a payment of between 5% to 20% of the profits and a nominal download fee, criminals are able to use the malware to generate a significant income.
Ransomware is lucrative. One of the most sophisticated strains of ransomware, CryptoWall, has been estimated to have netted its developers around $325 million in profit. Considerably more in fact, since the CyberThreat Alliance figures were calculated in 2015.
It is not difficult to see the attraction of ransomware. Because of the effectiveness of ransomware campaigns, we are only likely to see even more infections in 2016. In fact, this year there have been a number of ransomware infections reported by companies who have failed to protect networks from ransomware infections, leaving them little alternative but to pay to have their data unlocked. The victims include schools, healthcare providers, and even law enforcement departments. All organizations need to protect networks from ransomware or they may be left with little choice but to pay a ransom to unlock their files.
Who Is Being Targeted with Ransomware?
In the majority of cases, individuals and businesses are not actually targeted. Ransomware is sent out randomly via spam email. Oftentimes, millions of emails are sent in a single campaign. It is a numbers game and a percentage of emails will be opened, a smaller number of machines will be infected, and organizations that have failed to protect networks from ransomware are likely to have to pay the ransom.
However, businesses are also being targeted by attackers as the money that can be demanded to unlock devices – and networks – is much higher. A business may decide to pay several thousand dollars to recover critical data. Hackers and cybercriminals know this and are targeting organizations with spear phishing emails designed to get users to visit malicious websites that download ransomware. Spam emails are also sent with the malware disguised as invoices or even image files.
How Much Are Cybercriminals Asking to Unlock Encrypted Devices?
While single users receive $500 demands, the same cannot be said of businesses. Attackers can demand whatever fee they want. In February, Hollywood Presbyterian Hospital felt that paying a $17,000 ransom was the most logical solution considering the cost of data loss, downtime, and the restoration of its systems. The effort required and the cost of rectifying an infection could exceed the ransom cost by several orders of magnitude.
Horry County school district in South Carolina paid a ransom of $8,500 to decrypt 25 servers. The FBI investigated and told the school it had no alternative but to pay the ransom if it wanted to recover its data. In 2015, the Tewkbury, Mass., Police Department was also forced to pay up after it suffered a CryptoLocker attack. While data could be restored from a backup, the most recent file was corrupted and the only viable backup was more than 18 months old. In late February, 2016., Melrose Police Department, Mass., also paid a ransom to unlock files.
Is There an Alternative to Paying A Ransomware Ransom?
Depending on the type of ransomware used by cybercriminals in their attack, it may be possible to unlock data without paying a ransom. In some cases, data may not actually be locked at all. Users may just be fooled into thinking that it is.
Scareware is used to fool users into thinking they have been attacked with ransomware, when in actual fact they have not. Paying the ransom will remove the scareware from the device, but since no files have been encrypted, it is possible to remove the malware without paying the ransom. Many security tools can be used. In fact, that is how the attackers often make their money. By selling victims a security tool to remove their own infection.
Kovtar ransomware is a little different. This malware locks a computer and displays a message that cannot be removed. A lock screen is used which is displayed on boot, which prevents the user from using their device. It resides in the registry, but can be removed without paying a ransom. It has been commonly used as a police scam, claiming the user had visited websites displaying child pornography, even though in all likelihood they did not. It displays an FBI or police department warning, and demands that a payment be made to avoid any further action.
However, ransomware that actually encrypts files is a different beast entirely. Encryption cannot be unlocked without a security key, although it may be possible to restore files from a backup or with a system restore. Provided of course that those files have not also been encrypted. Some ransomware encrypts the files needed to restore data from a backup, or the backup files themselves.
When files have been encrypted, even the FBI has advised individuals to pay the ransom. In 2015, Joseph Bonavolonta, FBI cybercrime chief in Boston, was quoted as saying, “To be honest, we often advise people just to pay the ransom.”
The FBI says that most ransomware attackers are true to their word and supply the keys. That is not necessarily the case though. The keys may not be supplied and the individual could receive a further demand. Some ransomware that has been tweaked has been broken, making it impossible to decrypt locked files. Paying the ransom in such cases would not allow data to be recovered. There is no guarantee that payment of a ransom will result in a working key being provided. It is therefore essential to implement a number of measures to protect networks from ransomware infections.
How to Protect Networks from Ransomware?
There are a number of strategies that can be adopted to protect networks from ransomware infections and to reduce the damage caused if security defenses are breached.
Perform Regular Backups
Performing daily and weekly backups is essential. This measure will not protect networks from ransomware, but it will reduce the damage cause if an infection occurs. Backups of data should ensure files can be recovered. However, backups cannot always be restored. Just as the Tewkbury Police Department. It is essential that backups are not stored on portable devices that are left connected to computers. Ransomware can encrypt portable drives and can scan and lock files on networks, not just on individual devices.
Use a Spam Filter
Ransomware is often spread via spam email. One of the best ways to protect networks from ransomware is to prevent spam email from being delivered. Using a robust spam filtering solution will ensure the majority of malicious emails are caught and quarantined to prevent them from being opened by end users.
SpamTitan blocks 99.9% of spam emails, greatly reducing the likelihood of employees infecting their computers and corporate networks with ransomware.
Train Staff How to Identify Malicious Emails
Staff training is essential and a great way of helping to protect networks from ransomware. Emails are occasionally delivered to inboxes even with a robust spam filter in place. Employees must therefore be made aware of the risk and taught best security practices to avoid compromising their network or infecting their devices. Employees should be told never to open an email attachment that has been sent from someone they do not know. They should always check the email address of the sender carefully. Unfortunately, ransomware is not only spread via spam emails and web-borne attacks are more difficult to identify.
Use WebTitan to Block Malicious Websites
Cybercriminals use malicious advertising – terms malvertising – to lure individuals onto malicious websites where drive-by ransomware downloads take place. These adverts are often placed on legitimate websites via third party advertising networks. Malicious links are also posted on social media networks. Phishing emails also contain links to malicious sites that download ransomware.
One of the best ways that businesses can reduce the risk of a web-borne attack and protect networks from ransomware infections is by limiting the websites that can be accessed via their Wi-Fi and hard-wired networks. Blocking websites known to contain malware, preventing the downloading of file types commonly associated with ransomware, and blocking third party adverts from being displayed can all greatly reduce risk. To do this, a web filter is required.
WebTitan Cloud for Wi-Fi and WebTitan Gateway can be used by businesses, schools, and operators of Wi-Fi networks to reduce the risk of a ransomware attack. WebTitan blocks users from engaging in risky online behaviors and visiting malicious websites. Regardless of the level of training provided to users of computer networks, it is not possible to eliminate risk entirely. Using a web filtering solution to protect networks from ransomware, along with staff training and a spam email filter can greatly improve security posture.
The cost of these protections for businesses, educational institutions, and healthcare organizations is likely to be far lower than the cost of paying a ransom.