The attackers were trying to exploit an old PHP vulnerability, so DiMino intentionally configured his system to be vulnerable so he could track their intentions. The vulnerability is known as CVE-2012-1823 and was patched in PHP 5.4.3 and PHP 5.3.13 in May 2012, suggesting the attack targeted neglected servers whose PHP installations haven't been updated in a long time.
After allowing his honeypot system to be compromised, DiMino saw attackers deploy malware written in Perl that connected to an Internet Relay Chat (IRC) server used by attackers for command and control. The bot then downloaded local privilege escalation exploits and a script used to perform Bitcoin and Primecoin mining -- an operation that uses computing power to generate virtual currency.
"Most servers that are injected with these various scripts are then used for a variety of tasks, including DDoS, vulnerability scanning, and exploiting," DiMino said Tuesday in a blog post that provides a detailed analysis of the attack. "The mining of virtual currency is now often seen running in the background during the attacker's 'downtime'."
DiMino's report comes after researchers from security vendor Symantec warned in November that the same PHP vulnerability was being exploited by a new Linux worm.
The Symantec researchers found versions of the worm not only for x86 Linux PCs, but also for Linux systems with the ARM, PPC, MIPS and MIPSEL architectures. This led them to conclude that the attackers behind the worm were also targeting home routers, IP cameras, set-top boxes and other embedded systems with Linux-based firmware.
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