Botnet command & control malware – the highs and lows of 2018

Here’s an overview of the malware that botnet C&Cs were associated with, but if you want the full botnet C&C picture download the detailed report here.

The malware trends in 2018:

As always, the threat landscape was highly dynamic in 2018. While some trends such as remote access tools (RATs) continued to gather momentum, additional ones started to rear their heads, such as CoinMiners.

Credential Stealers: As in 2017, credential stealers were still accounting for the most significant amount of botnet C&C traffic; however there were changes as to which were top of the leader board.

Pony’ held the #1 spot for two years, however in 2018 ‘Loki’ took pole position, having more than doubled the number of unique botnet C&Cs associated with it.

Remote Access Tools (RATs): This type of malware saw a significant increase in 2018, in particular, a Java-based RAT, called JBifrost (aka Adwind).

Back in 2017, we reported that JBifrost was starting to flood the botnet landscape, however, in 2018 we witnessed an explosion in the number of unique botnet C&C listings associated with it. The sheer volume of these listings has placed JBifrost at #2 on our leader board.

Ransomware & e-banking Trojans: Botnet C&Cs associated with both types of malware dropped significantly in 2018.

CoinMiners: Making their first appearance in the Top 20 list last year were CoinMiners. These are malicious pieces of software that silently mine cryptocurrencies, such as Bitcoin and Monero, without the consent or approval of the user. In 2018, we identified 83 botnet C&Cs associated with CoinMiners.

Mining pools: In addition to CoinMiner botnet C&C listings, in 2018 we also issued 156 Spamhaus Block List (SBL) listings for 111 cryptocurrency mining pools that were used by the CoinMiners. Some of these cryptocurrency mining pools appeared to be rogue; however, the majority were legitimate pools that were being abused by CoinMiners.

The Spamhaus Project has tried to approach the responsible hosting providers, asking them to have the offending user(s) of the mining pool suspended, to stop the fraudulent activity. Unfortunately, this was not always possible because some cryptocurrencies, such as Monero, are entirely anonymous, unlike Bitcoin.

Mitigating the risk of malware at the DNS level

The increased threat from CoinMiners is apparent when you view the statistics from users of our DNS Firewall Threat Feeds. These threat feeds are consumed at the DNS level, allowing security teams to automatically block users (blocks/redirects), and IoT devices’ from accessing bad sites.

In April 2018 only 21% of blocks/redirects were for CoinMiner/Cryptoblocker traffic, whereas at the end of last year, in December 2018, CoinMiner redirects accounted for 66% of all blocked/redirected traffic.

It is evident that the botnet C&C landscape underwent some significant changes in 2018. With ‘lean teams’ and ‘lean budgets’ security professionals are caught between a rock and a hard place in attempting to keep on top of the ever-changing threats. Therefore, it’s crucial to identify solutions that are quick to install, ‘set & forget,’ and leverage the best threat intelligence in the industry. In doing so, security & IT teams are enabled to focus on other urgent matters, confident in the knowledge that teams of professional security researchers and investigators are identifying the threats on their behalf.