Additionally, there was no reason to believe that one would be able to decrypt one's files if one paid, the next ransom would probably be higher and paying only served to encourage criminals, the firm said. It has a website which offers a variety of tools for decrypting files.
The report, which focused on ransomware between April 2016 and March 2017, and compared the prevalence with the corresponding period a year earlier, also took in the WannaCry outbreak even though it occurred in May this year.
It defined ransomware as "so-called Windows blockers (they block the OS or browser with a pop-up window) and encryption ransomware" adding that the term also extended to "select groups of Trojan-Downloaders, namely those that tend to download encryption ransomware upon infection of a PC".
The ransom notice from the Petrwrap ransomware.
"The activity of mobile ransomware skyrocketed in early 2017 with 218,625 mobile trojan-ransomware installation packages – 3.5 times more than in the previous quarter. The activity then fell to the average level of the observed two-year period," the report said.
It said that there had been a rise in targeted attacks, with the focus being on financial organisations.
"In 2017 Kaspersky Lab identified eight groups, who have attacked financial organisations worldwide, including the PetrWrap authors, the infamous Mamba group, and six unnamed groups also targeting corporate users," the report said.
"In general, the tactics, techniques and procedures used by these groups are very similar. They infect the targeted organisation with malware through vulnerable servers or spear phishing emails. Then they establish persistence in the victim’s network and identify the valuable corporate resources to encrypt, subsequently demanding a ransom in exchange for decryption. In addition to their similarities, some groups have their own unique features."
The geographical appearance of ransomware was skewed to some extent as it was measured in countries that had at least 30,000 users of Kaspersky's customers.
In 2015-16, India was atop a list compiled measuring the percentage of users who were attacked by ransomware among all those hit by malware. Russia, Kazakhstan, Italy, and Germany all had percentages exceeding 4%.
A year later, Turkey topped this list, with Vietnam second. India dropped to third spot.
On WannaCry, the report noted that when the worm first hit, the number of Windows 7 systems affected were by far the majority (99.19%) compared to Windows XP (0.09%) and Windows 10 (0.72%). But a week later, on 19 May, there was a discernible change with Windows 7 dropping (93.25%) and Windows 10 gaining a great deal (6.06%) while Windows XP moved just a little (0.69%).
Kaspersky warned that ransomware-as-a-service was becoming more popular and very easy for anyone to join. "Today, an attacker (or group) can easily create their own encryptor without making any special
effort. A vivid example is the Mamba encryptor based on DiskCryptor open source software. Some cyber criminal groups do not even go to the trouble of involving programmers; instead, they use this legal utility (below) 'out of the box'."
It said that there were three main reasons:
- It’s easy to buy a ransomware build or builder on the underground market;
- It’s easy to buy a distribution service; and
- Crypto ransomware, as a business, has a very clear monetisation model through cryptocurrencies.
And there were three ways to enter the market:
- Create new ransomware for sale.
- Become a partner in a ransomware affiliate programme.
- Become the owner of an affiliate programme.
"Flexibility is the key feature of the current underground ransomware ecosystem," the report said. "It offers lots of opportunities to people with a propensity towards criminal behaviour, and it almost
doesn’t matter what level of IT experience they have."
The report is free and can be downloaded here.
Graphics: courtesy Kaspersky Lab.