The internet can be a hostile environment. The threat of cyberattack is ever-present as new vulnerabilities are released and a commodity of tools are produced to exploit them. Therefore, the pressure on organisations (and their employees) to protect customer data and defend against attacks, is mounting.
About the author
Tyler Moffitt, Security Analyst, Webroot.
As our 2019 Nastiest Malware List highlights, cyberattacks are becoming more advanced and difficult to detect. From ransomware strains to cryptomining campaigns – that deliver the most attack payloads beyond phishing – cybercriminals are making better use of stolen, personal information available to craft more convincing and targeted attacks.
Ultimately, what this means is that doing nothing is no longer an option. It’s time that organisations step up, learning how to spot potential threats and the implications behind these attack tactics. This starts with understanding the ‘nastiest’ threats out there today that are leaving businesses at risk.
Botnets: delivering mass disruption
Botnets have continued to dominate the infection attack chain in 2019. No other type of malware was responsible for delivering more ransomware and cryptomining payloads.
Emotet, which was the most prevalent malware of 2018, held onto that notorious distinction into 2019. While it was briefly shut down in June, Emotet returned from the dead in September, and remains the largest botnet to date, delivering various malicious payloads.
Trickbot has been partnering with banking Trojan groups like IcedID and Ursif in 2019. Its modular infrastructure makes it a serious threat for any network it infects and, when combined with Ryuk ransomware, it's one of the more devastating targeted attacks of 2019.
Dridex was once one of the most prominent banking trojans. Now it acts as an implant in the infection chain with the Bitpaymer ransomware and is achieving alarming success.
The triple threat of Emotet, Trickbot and Ryuk
Ransomware has been around for nearly a decade and it should come as no surprise that it’s still a firm favourite amongst cybercriminals. Ransomware remains a top threat, adopting a more targeted model last year. Small and medium-sized businesses (SMBs) are easy prey and make up most of its victims.
And one of the most menacing ransomware evolutions comes in the form of the ‘triple threat’ attack, involving Emotet, Trickbot and Ryuk. In terms of financial damage, this is probably the most successful chain of 2019. With more targeted, reconnaissance-based operations, they now assign a value to targeted networks post-infection will extort them accordingly after deploying ransomware.
As far as other ransomware strains are concerned, GandCrab is one of the most successful examples of ransomware-as-a-service (RaaS) to date, with profits in excess of $2 billion. While Crysis (aka Dharma) makes its second consecutive appearance on our Nastiest Malware list. This ransomware was actively distributed in the first half of 2019, with almost all infections we observed distributed through RDP compromise.
Email-based malware campaigns grow in their complexity and believability dramatically this year. Phishing became increasingly more personalised and extortion emails have begun claiming to have captured lude behaviour using compromised passwords.
Business Email Compromise (BEC) attacks also surged in 2019. Individuals who are responsible for sending payments or purchasing gift cards were targeted through spoof email accounts impersonating company executives or familiar parties. Victims are often tricked into giving up wire transfers, credentials, gift cards and more.
What many employees don’t realise is that often, the biggest security concern at the office is one of their co-workers, not a hacker in some remote location. A lack of best practices like poor domain administration, being reactive, not proactive, reuse and sharing of passwords, and lack of multi-factor authentication all mean bad actors may already be ‘phishing’ amongst them.
Cryptomining and Cryptojacking
Cryptojacking (also called malicious cryptomining) is an emerging online threat that hides on a computer or mobile device and uses the machine’s resources to “mine” forms of online money known as cryptocurrencies. It’s a menace that can take over web browsers and compromise all kinds of devices, from desktops and laptops, to smartphones and even network servers. And according to Webroot’s research, these attacks rise and fall with the relative market cap of cryptocurrency price. The largest campaign of cryptojacking this year is through the ‘Retadup’ attacks and the most innovative was ‘Hidden Bee’.
Hidden Bee tactics have a complex and multi-layered internal structure that is unusual among cybercrime toolkits, making it an interesting addition to the threat landscape. It first emerged last year with IE exploits and has now evolved into payloads inside JPEG and PNG images through Steganography and WAV media formats flash exploits. The additional difficulty in the analysis is introduced by the fact that the URLs and encryption keys are never reused and work only for a single session.
Whereas Retadup, is a cryptomining worm, that first started last year and was removed in August by Cybercrime Fighting Center (C3N) of the French National Gendarmerie, after they took control of the malware’s command and control server. It stealthily uses a computer’s processor to mine cryptocurrency, which generates money for the operators. It’s also able to run other types of malware, such as ransomware, and is commonly spread via attachments, file-sharing networks and links to malicious websites. Peak infection counts had Retadup on over 800k machines simultaneously.
Closing critical security gaps
These nastiest threats highlight how a comprehensive approach to endpoint security is needed now more than ever, to keep up with these various and complex attack models. Attackers may be using the same strains of malware, but they are making better use of stolen personal information available for more personalised threats. As a result, organisations need to adopt a layered security approach and not underestimate the power of consistent security training as they work to improve their cyber resiliency and protection.
After all, a business that practices good risk management not only protects its reputation, intellectual property and data, but will also offer its customers a measure of assurance making them attractive to do business with.
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