A grouping of similar threat activity dubbed “Blue Mockingbird” attempted to distribute Monero-mining malware payloads across its enterprise targets.

Red Canary Intel discovered that the earliest examples of Blue Mockingbird traced back to December 2019. In two of the incidents investigated by the security firm, the threat gained entry into a targeted organization’s network by exploiting a deserialization vulnerability (CVE-2019-18935) affecting public-facing web applications that implemented Telerik UI for ASP.NET AJAX. This process enabled the threat to upload two dynamic-link libraries (DLLs) to a Windows IIS web server’s web app.

The main payload dropped by Blue Mockingbird was XMRig, a well-known Monero-mining tool that adversaries have commonly incorporated into their attack campaigns. Not content with one victim, digital attackers commonly abused the remote desktop protocol (RDP) to move laterally throughout the network so they could distribute payloads throughout the enterprise. This increased the overall efficacy and profitability of a single attack instance.

Other Recent Monero-Mining Campaigns

Blue Mockingbird isn’t the sole Monero-mining attack campaign that’s targeted enterprises in recent years. Back in early 2018, for instance, Kaseya issued a series of patches in response to a vulnerability that some malicious actors had abused to target vulnerable organizations with Monero-mining software.

In May 2018, Imperva observed digital attackers exploiting a remote code execution (RCE) vulnerability to spread the ‘Kitty’ Monero miner. More than a year later in October 2019, Palo Alto Networks’ Unit 42 spotted a cryptojacking worm spreading through containers in the Docker Engine to activate a Monero miner.

Defend Against Blue Mockingbird

Security professionals can help defend their organizations against threat activity such as Blue Mockingbird by using risk assessments to determine the impact that a Monero-mining attack could have on their business assets. Infosec teams should also disable JavaScript in browsers wherever feasible and use updated threat intelligence to stay on top of the latest crypto-mining attacks.