A new report by anti-phishing training company PhishMe shows a marked rise in the volume of ransomware emails in March. The report shows that spam emails are now predominantly being used to deliver ransomware to unsuspecting victims. The spike in ransomware emails highlights how important it is to conduct anti-phishing training and to use anti-spam solutions to prevent the malicious file-encrypting software from being delivered to employee’s inboxes.
Spike in Ransomware Emails as Criminals Seek Easy Cash
Ransomware has been around for about a decade, yet it has not been favored by cybercriminals until recently. Throughout 2015, under 10% of phishing emails were being used to transmit ransomware. However, in December there was a major spike in ransomware emails, which accounted for 56% of all phishing emails in December. The upward trend has continued in 2016 and by March, 93% of phishing emails contained ransomware – or were used to infect users by directing them to malicious websites where drive-by downloads of the malicious software occurred.
Spam email volume has been in general decline, in no small part to the shutting down of major botnets in recent years. However, that does not mean that the threat of cyberattacks via email can be ignored. In fact, PhishMe’s figures show there has been a surge in the number of phishing emails being sent. In the first quarter of 2016, the number of detected phishing emails soared to 6.3 million, which represents a 789% increase from the volume captured in the last quarter of 2015.
Ransomware is increasingly being used by cybercriminals for a number of reasons. Ransomware is now easy to obtain and send out. Many ransomware authors offer ransomware-as-a-service to any criminal looking to make a quick buck. Not only can the ransomware be hired for next to nothing, instructions are supplied on how to use it and criminals are allowed to set their own ransoms and timescales for payment. All they need to do is pay a percentage of the ransoms they obtain to the authors.
What makes the use of ransomware even more attractive is the speed at which criminals can get paid. Time limits for paying ransoms are usually very short. Demands for payment within 48 hours are not uncommon. While phishing emails have commonly been used to obtain credit card details from victims, which then need to be sold on, criminals can run a ransomware campaign and rake in Bitcoin payments in just a few days.
The ransoms being demanded are also relatively low. This means that many individuals can afford to pay the ransom to obtain the decryption keys to unlock their files, and businesses are also likely to pay. The cost of recovering data and restoring systems, together with the lost revenue from the time that computer systems are down, is often less than the ransom being demanded.
Ransomware Is Becoming Much More Sophisticated
The latest forms of ransomware now being used – Locky, CryptXXX, TeslaCrypt, and Samas (Samsam) – are capable of spreading laterally. Not only can the ransomware infect files on a single computer, other networked computers can also be infected, as can network drives, servers, portable storage devices, and backup drives. Some forms are also capable of deleting Windows shadow copies and preventing the restoration of files from backups.
All that the criminals need is for one business computer to be infected in order to encrypt files throughout the network. That means only one end user needs to be fooled into opening an infected attachment or visiting a malicious webpage.
Ransomware emails often contain personal information to increase the likelihood of an individual clicking a malicious link or opening an infected attachment. Word files are now commonly being used to infect users. Embedded macros contain code that downloads the malicious payload.
The malicious software is sent out in spear phishing campaigns targeting one or two users in a company, such as accounts and billing department executives. Personal information is often used in the emails – names, addresses, and job titles for example – to increase the likelihood of attachments being opened and links being clicked.
As criminals get better at crafting phishing emails and the ransomware becomes more sophisticated, it is more important than ever to use anti-spam solutions such as SpamTitan to trap ransomware emails and prevent them from being delivered. SpamTitan traps 99.9% of spam emails, helping organizations protect their networks from ransomware attacks.