WatchGuard also reported that almost half of zero-day malware is now delivered via encrypted connections, and warned organisations that if they are not decrypting these connections they will have poor visibility of the amount of malware hitting their networks.
While unpatched vulnerabilities in older versions of Windows and Office remain fertile soil for attackers, they are also exploiting flaws in the latest versions of Microsoft's widely used products.
Overall network attack detections fell by 21%, but that only took the volume back to the Q1 2021 level, which was higher than the previous year. WatchGuard suggests this change could indicate a shift towards more targeted attacks.
The top 10 network attack signatures accounted for 81% of detected attacks, and there was only one new signature in the top 10 in Q3: 'WEB Remote File Inclusion /etc/passwd' (1054837), which targets older and still widely used Microsoft Internet Information Services servers. The most commonly detected signature is still the SQL injection signature which has held that place since Q2, 2019.
Scripting attacks on endpoints in the first three quarters of 2021 were 10% higher than the whole of 2020, and that year saw a 666% increase on the 2019. "Even those with limited skills can often fully execute a malware payload with scripting tools like PowerSploit, PowerWare and Cobalt Strike, while evading basic endpoint detection," warned WatchGuard.
A protocol flaw in Microsoft's Exchange Server Autodiscover system allowed attackers to compromise several normally trustworthy domains, and this was used in a variety of ways, including the installation of cryptominers, key loggers and remote access trojans (RATs), and to fake SharePoint sites in order to harvest Office365 login credentials. The number of blocked domains was down 23% from the previous quarter, but is still several times higher than it was in Q4 2020, highlighting the importance of keeping servers, databases, websites, and systems patched to limit exploitation.
Ransomware bounced back to 105% of 2020 volume by the end of September, and is expected to reach 150% in the Q4 2021 statistics. 2021 data is analysed. Ransomware-as-a-service operations such as REvil and GandCrap make it easy for criminals to run malware campaigns and in return receive a percentage of the ransom.
The top security incident during Q3 2021, according to WatchGuard, was the REvil ransomware-as-a-service based attack on Kaseya VSA Remote Monitoring and Management software. Ransomware was delivered to some 1500 organisations and potentially millions of endpoints. Fortunately, the FBI eventually obtained the decryption key, but the incident was a reminder of the need to keep systems patched, and to adopt zero-trust and the principle of least privilege for vendor access.
"While the total volume of network attacks shrank slightly in Q3, malware per device was up for the first time since the pandemic began," said WatchGuard CSO Corey Nachreiner.
"Looking at the year so far as a whole, the security environment continues to be challenging. It's important that organisations go beyond the short-term ups and downs and seasonality of specific metrics, and focus on persistent and concerning trends factoring into their security posture.
"An important example is the accelerating use of encrypted connections to deliver zero days. We continue to believe that the WatchGuard Unified Security Platform offers the best comprehensive protection for combatting the variety of threats organisations face today."
WatchGuard's complete Q3 2021 Internet Security Report is available here.