An Oracle WebLogic vulnerability fixed in October last year is being exploited on unpatched machines to mine Monero, a cryptocurrency, and other lesser-known imaginary coins.
Writing for the the SANS Technology Institute, Renato Marinho, chief research officer at Morphus Labs, on Monday said a recently disclosed software bug – specifically, poor input sanitization in
wls-wsat, a WebLogic component – can be exploited to allow an unauthenticated attacker to run arbitrary commands with server user privileges.
The vulnerability also affects Oracle's PeopleSoft software, which can include WebLogic as a server.
In a follow-up post on Tuesday by Johannes B. Ullrich, SANS Dean of Research, explained that a proof of concept exploit was published by Lian Zhang, a Chinese security researcher, on his blog in December. By the end of that month, he said, a working exploit designed to install cryptomining code began showing up.
The exploit downloads a bash file that chooses a suitable working directory, kills active crypto mining on the system, and creates a CRON job to download new mining code, identified as either XMRig or fs-manager.
Eye off the ball
The attack appears to be difficult to miss because it also kills the WebLogic service on the target machine. But at cloud providers, evidently, customers aren't paying very close attention.
Ullrich says a log from a compromised system covering the five day period from January 4th through January 9th this year shows 722 affected IP addresses at various locations around the world.
Many of the affected hosts are at cloud service providers: ~144 at Amazon Web Services, ~41 at Digital Ocean, ~33 at Google Cloud, ~30 at Microsoft Azure, ~30 at Oracle Cloud, and ~17 at OVH.
"This isn’t a surprise since many organizations are moving their most critical data to the cloud to make it easier for the bad guys to get to it," quipped Ullrich.
Ullrich said XMRig is legitimate crypto-mining code, and recounted Marinho's recovery of a configuration file showing one miner managed to collect 611 Monero coins, worth about $226,070 in theory.
However, that purse appears to have been collected over a long period of time, perhaps through other avenues, because the user's 450 KH/s hash rate could only generate about $31,000 in fantasy coins a month.
Marinho also found files for another group's attempt to use the same vulnerability to mine AEON, a lesser known cryptocurrency.
Rather wryly, Ullrich observed, "Even though they are achieving a similar hash rate, they only earned about $6,000 so far. Maybe they will switch to Monero after reading this." ®