Linux Ransomware Has Predictable Key, Automated Decryption Tool Released (csoonline.com)
itwbennett writes: Last week a new piece of ransomware was discovered that targets Linux servers. Yesterday, researchers at Bitdefender discovered a critical flaw in how the ransomware (dubbed Linux.Encoder.1) operates while testing a sample in their lab and released a free tool that will automatically decrypt any files on a victim's system that were targeted.
"Typically, the malware is injected into Web sites via known vulnerabilities in site plugins or third-party software — such as shopping cart programs. ref
"Once launched with administrator privileges, the Trojan loads into the memory of its process files containing cybercriminals' demands:" ref
I had a server hit by this a few weeks ago. Got the same ransom message shown there. I'm fairly sure it didn't require root, in fact it only encrypted files that were writable by www-data and not the handful in /var/www that were owned by root. The README_FOR_DECRYPT.txt file that was left in every directory was also owned by www-data.
I'm not sure what was posted in, but the infection mechanism appears to be this single request
46.160.xxx.xxx - - [19/Oct/2015:05:14:06 -0400] "POST /wp-content/include.php HTTP/1.0" 404 135395 "-" "Mozilla/5.0 (Windows NT 6.1; rv:10.0.1) Gecko/20100101 Firefox/10.0.1"
I'm still not really sure how that caused an infection, but i'm guessing it exploited something in the wordpress 404 handler? I don't see any other request from that IP and the server load spiked right after that as the files starting being encrypted.