Skip to content Skip to footer

Webroot reveals 2020’s nastiest malware

Webroot has released its annual list of ‘Nastiest Malware’, revealing phishing, botnet attacks and ransomware as 2020’s most vicious cybersecurity threats.

It’s no surprise that cybercriminals have taken advantage of the global pandemic, as millions have been forced to shift how they work and live, to find ways to make old tricks new again. 

Without further or do, the list is as follows:


Phishing is a key part to a malware campaign’s effectiveness, and its popularity with cybercriminals has not stopped growing since it first emerged decades ago.

Getting a victim to fall for phishing is the first step in many infections, which will lead to theft of important credentials, further malicious payloads on the machine, and eventual ransomware infections.

This year, many threats are taking advantage of the situation created by the pandemic, and almost all the malicious spam emails (malspam) phishing lures used by malware are based on Covid-19. Here are some of the ones we’ve seen:

1. CDC/WHO/White House Guidelines for the Covid-19 Pandemic: This one is a fake statement from government or health officials that supposedly contains information on quarantine rules and health and safety. 

2. Updated list of new Covid-19 cases around your city: This fake claim is very apparent, not only because of privacy issues, but because it relies on the heightened sense of fear and tension created by the pandemic to lower victims’ suspicion levels and make them more likely to fall for the scam.

3. Fill out this form to receive your Covid-19 stimulus: Before the stimulus was issued, many people in the US were curious how to receive the $1,200 they had been promised.


Ransomware did everything but slowdown in 2020, largely due to Covid-19 phishing lures, with several notable attacks from healthcare to municipalities to education.

Ransomware encrypts a victim’s files and then demands payment in order to restore access. In 2020, a new trend emerged with ransomware gangs creating ‘leak sites’ where they expose or auction off a victim’s sensitive data if they refuse to pay. The three nastiest ransomware threats include.

1. Conti/Ryuk: The FBI named Ryuk the most successful ransomware of 2019 in terms of payments reported to the FBI (note: this is based on cases reported. Many go unreported.)

The second version of Ryuk was rebranded to Conti, which is a common tactic ransomware authors use to avoid attention.

We’ve seen Conti deployed from RDP, but through phished or stolen credentials (likely grabbed using TrickBot, QakBot, or another Trojan, which themselves were likely dropped after an initial Emotet infection) not brute-forced via unsecured RDP.

These ransomware authors also threaten to leak stolen data on their leak/auction site to discourage non-payment.

2Sodinokibi/REvil/Gandcrab Ransomware: GandCrab, Sodinokibi and REvil are all iterations of the same ransomware and likely sound familiar if you’ve seen our annual list before.

This ransomware as a service (RaaS) payload is available for anyone to use, as long as the authors get a cut of any successful ransoms. 

3. Crysis/Dharma/Phobos Ransomware: These ransomwares as a service (RaaS) payloads are almost exclusively deployed using compromised RDP credentials that are either brute-forced or easily guessed.

We believe these to be clones of one another by the same group of malware authors, and their payloads are available for hire. Unsecured RDP has risen in prevalence during the Covid-19 pandemic, so payloads that take advantage are likewise on the rise.

RDP attacks also have the added benefit (for the criminals, anyway) of not needing a human victim to fall for a phishing attack to download the payload.

Botnets and Trojans

Botnets continue to be a dominant threat in the security landscape. They are essential to the success of ransomware, and many of the top offenders listed below have close ties to top ransomware.

Botnets are responsible for most of the malicious spam email campaigns and after a user clicks to infect themselves from email, they gain foothold in the environment, so the eventual ransomware payload does as much damage as possible. The nastiest botnet and Trojan threats include: 

1Emotet: The Emotet botnet continued its run as the nastiest threat for the third year in a row.

It is responsible for the most ransomware infections, making it pretty nasty. Emotet has recently resurfaced during the Covid-19 lockdown with new pandemic-themed phishing campaigns.

Due to its ability to get around many anti-spam technologies and make it into the inbox, Emotet has what may be the largest number of partnerships with other malware groups, including TrickBot, Dridex, QakBot, Conti/Ryuk, BitPaymer and REvil.

2. TrickBot: This popular banking and info-stealing Trojan used to just make money through web injects to steal credentials.

Now upgraded, it is typically deployed as second stage from Emotet that leads to ransomware, likely Conti/Ryuk, but we’ve seen cases without Emotet this year as well.

Once on a machine, TrickBot moves laterally throughout the network using exploits to propagate and gather as many credentials as possible, often over weeks or even months, until it obtains domain credentials.

After that, the criminal who deployed the infection would have full control of the network environment, allowing them to disable protections and ensure the greatest amount of damage when they launch the ransomware piece.

3Dridex: Another very popular banking/info-stealing Trojan that’s been around for years, Dridex typically deploys ransomware like BitPaymer/DoppelPaymer. It is either dropped via Emotet or its authors’ own malicious spam campaign.

Like TrickBot, Dridex spreads laterally and aims to steal domain credentials, dropping Dridex loaders on every machine it encounters. It then tries to stay under the radar, stealing info until it successfully grabs domain credentials.

Again, with domain credentials, the bad actor can disable protections and target specific systems with ransomware to ensure maximum damage.

Mobile Threats

2020 has brought an unexpected rise in mobile threats, earning them an honourable mention on this year’s list.

Many of them masquerade as Covid-19 tracing apps, preying on the fear generated by the pandemic. Others abuse app accessibility features to steal user information. The nastiest mobile threats include:

1. Joker: While Joker has only been around since 2019, it has shown up in the Google™ Play Store with much more frequency this year due to skyrocketing popularity. It simulates other legitimate apps to try to steal credit card information and/or banking credentials.

2. CryCryptor: Discovered just this year, this mobile ransomware variant is based off the open-source ransomware CryDroid and has been spotted masquerading as Covid-19 tracing apps.

3. EventBot: A new Banker variant that was also discovered 2020, EventBot abuses accessibility features to steal user data, and reads and steals SMS messages to bypass two-factor authentication.

4. Dingwe: An early Android™ remote access tool (RAT), Dingwe was modified and re-discovered in 2020. It is capable of controlling a device remotely, and many samples have been found impersonating as COVID-19 tracing apps.

Tyler Moffitt, security analyst at Webroot commented, “2020 has been a year of change, but one thing remains consistent: cybercriminals are relying on same old tricks to secure their financial treats, because they continue to be successful.

“The pandemic has resulted in more distractions for online users and lowered overall scepticism in a more casual, remote work environment.

“These vulnerabilities create opportunities cybercriminals, making it increasingly critical to prioritise cyber resilience for people, devices and cloud, before it’s too late.”

You may also like

Stay In The Know

Get the Data Centre Review Newsletter direct to your inbox.