Cybersecurity Advice

How to Prevent Ransomware Attacks

Dec 30, 2016 | Cybersecurity Advice, Network Security, Web Filtering

Cybercriminals have embraced ransomware and have been increasingly targeting businesses, yet many business leaders are unsure how to prevent ransomware attacks. Consequently, the risk from ransomware is not being effectively managed, and that may prove costly.

Ransomware is a form of malware that is capable of encrypting files on local machines, network drives, and servers. Any computer that is connected to the Internet can potentially be infected. Even without internet access, files may be encrypted if a computer is networked. The latest ransomware variants are capable of spreading laterally within a network and encrypting the data on hundreds of devices.

Files required for critical business processes may be encrypted and made inaccessible. A successful attack can result in a company’s operations grinding to a halt. A healthcare ransomware attack can result in patients’ health information becoming inaccessible. An attack on a pharmaceutical company may result in files necessary for drug manufacture being locked, which could affect the quality of products. Lawyers offices may lose essential client information. Few businesses could continue to operate at their full potential during a ransomware attack.

The loss of files can prove extremely expensive, far less than the cost of any ransom payment. Many companies therefore are left with little alternative but to pay the ransom demand. Ransom payments are actually made surprisingly frequently. According to a recent study conducted by IBM, 70% of businesses that experienced a ransomware infection ended up paying the attackers to supply the keys to unlock their data. Half of those businesses paid more than $20,000 while 20% paid more than $40,000.

Even when the ransom is paid there is no guarantee that a viable key will be supplied to unlock the encryption. Files may therefore be lost forever. One healthcare organization in the United States recently discovered that files can all too easily be lost forever. Three months after ransomware was installed on one of its servers and critical patient health information was encrypted, Desert Care Family and Sports Medicine has still not been able to unlock the encryption nor access its patients’ data.

It is essential to learn how to prevent ransomware attacks and to implement appropriate defenses not only to stop attackers from installing ransomware, but to ensure a system is put in place that will allow data to be recovered without having to resort to paying a ransom.

Recovering from a ransomware attack can be extremely expensive. Ransom payments can be extortionate. Business can be lost while systems are taken out of action. Even applying keys that have been supplied by attackers can be long winded. Each encrypted device has its own key, and those keys must be applied very carefully. A forensic analysis is also important after a ransomware attack to search for backdoors that may have added, as well as to determine if data have been stolen. Additional protections then need to be put in place to prevent future attacks from occurring.

How to Prevent Ransomware Attacks

The first and most important step to take will not prevent ransomware attacks, but it will help you to recover from a ransomware attack promptly without having to resort to paying the ransom. Recovery will depend on you having a viable backup of your data. Total file recovery may not be possible, but it should be possible to recover the vast majority of your files.

For that to be possible, you must ensure that all files on all devices and network drives are backed up. That includes all removable drives such as flash drives. Backup files must be stored on a non-networked drive, in the cloud, or ideally on an air-gapped device – One that is unplugged as soon as the backup is performed. Multiple backups should ideally be made with one copy stored in the cloud and one on a detachable storage device. You should always store backups in multiple files. If one becomes corrupted, you will not lose all of your data.

• Avoid the use of administrator accounts with extensive privileges as far as is possible. If an administrator account is required, use it and then change to a guest account with limited privileges. This will reduce the damage caused if the user’s machine is infected.
• Ensure that all software is kept up to date and your organization employs good patch management practices. In particular, ensure browser and plugin updates are applied promptly. Vulnerabilities can all too easily be exploited and used to download ransomware.
• If plugins are not required, remove them. Adobe Flash in particular, but also Java and Silverlight. If required, they should require activating individually as and when needed.
• Ensure employees’ computers are configured to show file extensions. If full file extensions are displayed, it is easier to identify potentially malicious files with double extensions.
• Ensure macros are disabled on all devices. At the very least, ensure macros do not run automatically.
• Disable Remote Desktop Protocol (RDP) on all devices unless it is absolutely essential.
• A web filter can be used to prevent end users from visiting malicious websites where ransomware can be downloaded. A web filter can also block malicious third party adverts (malversting).
• End users should be instructed never to open files from unknown senders or to click on links contained in emails unless 100% sure that the links are genuine.
• The use of a spam filter is strongly advisable. The spam filter should be configured to aggressively block threats. Executable file attachments should also be automatically quarantined.

How to Reduce Risk of Malware Infections from Websites

May 13, 2016 | Cybersecurity Advice, Network Security, Web Filtering

To reduce the risk of malware infections from websites you can avoid certain types of sites that are commonly used by cybercriminals to infect visitors. Sites containing pornography for instance, torrents sites, and online marketplaces selling illegal medication for example. However, while these sites are often compromised with malware or contain malicious code, they are far from the most common sites used by cybercriminals to infect visitors.

The unfortunately reality is that browsing the Internet and only visiting what are perceived to be “safe sites” does not mean that you will not be exposed to maware, malicious code, and exploit kits. Hackers are increasingly compromising seemingly legitimate websites to redirect visitors to sites containing exploit kits that download malware and ransomware.

Two CBS-affiliated news websites were recently discovered to be hosting malicious adverts that redirect visitors to sites containing the Angler Exploit Kit. MSN has been found to host malvertising in the past, as has Yahoo. A study conducted by anti-virus company Symantec revealed that three quarters of websites contain security vulnerabilities that could potentially be exploited to infect visitors with malware.

High Profile Websites Compromised and Used to Deliver Ransomware to Visitors

This week, two new websites were found to have been compromised and were used to infect visitors with malware.

The celebrity gossip website PerezHilton.com may cause problems for celebrities, but this week it was also causing problems for its visitors. The site attracts millions of visitors, yet few would suspect that visiting the site placed them at risk of having their computer files locked with powerful file-encrypting ransomware.

However, that is exactly what has been happening. Hackers compromised an iframe on the site and inserted malicious code which redirected visitors to a website containing the Angler Exploit Kit. Angler probes visitors’ browsers for security vulnerabilities and exploits them; silently download a payload of malware. In this case, the Angler Exploit Kit was used to push Bedep malware, which in turn silently downloaded CryptXXX ransomware onto the victims’ devices.

A second malvertising campaign was also conducted that redirected visitors to a different website. The exploit kit used to infect redirected visitors was different, but the end result was the same. A malicious payload was downloaded onto their devices.

Another well-known website was also discovered to have been compromised this week. The website of the world renowned French film production company Pathé was discovered to have been compromised. Hackers had managed to embed malicious code in one of the webpages on the site. The code also redirected users to a site hosting the Angler Exploit Kit, which similarly was used to infect visitors with CryptXXX ransomware.

How to Reduce the Risk of Malware Infections from Websites

Exploit kits take advantage of security vulnerabilities in browsers. To reduce the risk of malware infections from websites it is essential that browsers are kept up to date. That includes all browser plugins. If no security vulnerabilities exist, there would be nothing for exploit kits to exploit.

However, zero-day vulnerabilities are emerging all the time and software manufacturers are not always quick to develop fixes. Adobe was alerted to a new zero-day vulnerability a few days ago, yet they only just released a fix. During that time, the vulnerability could have been exploited using exploit kits. Cybercriminal gangs are quick to incorporate new zero-day vulnerabilities into their exploit kits and do so faster than software companies can release fixes. Ensuring all updates are installed promptly is a great way to reduce the risk of malware infections from websites, but additional measures need to be taken.

If you really want to improve your – or your company’s – security posture and really reduce the risk of malware infections from websites, you should use a web filtering solution. This is particularly important for businesses to ensure that employees do not inadvertently compromise the network. It can be difficult to ensure that all devices used to connect to the network are kept 100% up to date, 100% of the time.

A web filtering solution can be configured to block malvertising, blacklists can be used to prevent compromised websites from being accessed, and malware downloads can be prevented. Along with good patch management practices, it is possible to effectively reduce the risk of malware infections from websites.

How to Protect Networks from Ransomware

Mar 10, 2016 | Cybersecurity Advice, Network Security, Web Filtering

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.