Ransomware pushers up their game against small businesses

The majority of clicks on recent links spreading CryptoWall and TorrentLocker came from small and medium-sized businesses

After extorting millions from consumers over the past few years, file-encrypting ransomware creators are increasingly focusing their attention on victims who are more likely to pay up: small and medium-sized businesses.

Throughout June and July, over 67 percent of users who clicked on malicious links in CryptoWall-related emails were from the SMB sector, researchers from antivirus vendor Trend Micro found. An additional 17 percent were from within large enterprises.

CryptoWall is one of the most widespread ransomware programs, infecting nearly 625,000 systems between March and August 2014 and many more since then. Researchers estimate that it has earned well over $1 million for its creators.

Trend Micro's statistics for another common ransomware program known as TorrentLocker also suggests that SMBs are increasingly being targeted.

Small and medium-sized companies accounted for over 40 percent of clicks on TorrentLocker-related URLs in June and July. The number exceeds 50 percent when large enterprises are included.

However, unlike big companies, SMBs are less likely to use sophisticated security and backup solutions that can prevent ransomware infections and help them recover encrypted files, the Trend Micro researchers said in a blog post.

Compared to consumers, SMBs are also more likely to give into this type of extortion because the files stored on their computers are often critical to their operations and also because they can afford paying the ransoms, which typically exceed $500.

Trend Micro researchers have seen many emails that were crafted specifically for business users during recent ransomware-related spam campaigns. Some of the most common lures include resumes, customer orders, passport scans, as well as notifications from postal services, telecommunications companies, utilities and government bodies.

TorrentLocker in particular is well known for its localization efforts. For example, in Turkey the ransomware gang often sends emails that masquerade as notifications from a courier service called Turkish Cargo or mobile operator Turkcell. In Italy, it impersonates a courier service called SDA, a utility company called Enel and, more recently, the mobile operator Telecom Italia Mobile.

"Some of TorrentLocker’s social engineering tactics are consumer-focused, as exemplified by bogus speeding fines sent by the Australian Federal Police (AFP) in Australia," the Trend Micro researchers said. "However, most of the lures are compatible with business targets, such as parcel notifications, which are an important part of a small business’ day-to-day activity. In short, TorrentLocker targets both consumers and SMBs."

Another indication that businesses are now the primary target is that ransomware spam campaigns are timed to coincide with the start of the work day in different regions. Based on Trend Micro's data, most people click on the malicious ransomware links between 9am and 1pm when they would normally be at work.

The cybercriminals behind these operations are also increasingly adding detection evasion techniques, the Trend Micro researchers said.

For example they're using legitimate, but compromised websites to redirect users to the final landing pages. They're also adding CAPTCHA tests to their spoofed sites in order to block automatic crawlers or security sandboxes from catching the malicious payloads.

Some recent TorrentLocker versions even have self-destruct capabilities to prevent IT staff from collecting samples from infected systems.

"We believe that ransomware will continue to improve its tactics and target more business environments," the Trend Micro researchers said. Simple things like verifying the source of emails and the reputation of websites before visiting them can go a long way to prevent ransomware infections. However, the importance of backing up data using the 3-2-1 rule -- at least three copies in two different formats with one copy stored off-site -- cannot be stressed enough, they said.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?