In each circumstances the attackers used the vulnerability to add encrypted recordsdata with the extension .txt which had been then decoded utilizing the Certutil WIndows utility into .jsp recordsdata that served as internet shells — backdoor scripts that enable attackers to distant execute instructions on a server. In one of many incidents the attackers created a staging folder the place they dropped a number of utilities: a cookie exporting DLL file that’s a part of Microsoft’s Edge browser, a community useful resource scanner referred to as fscan.exe, a replica of the Microsoft Useful resource Compiler, and different executables.
The malicious internet shell additionally contained code that tried to decrypt passwords for ColdFusion knowledge sources. ColdFusion saves passwords in encrypted type with a seed worth that was hard-coded in ColdFusion 8, however is exclusive for every set up in later variations.
“A menace actor who has management over the database server can use the values to decrypt the info supply passwords in ColdFusion model 8 or older,” CISA explains. “The sufferer’s servers had been operating a more moderen model on the time of compromise; thus, the malicious code didn’t decrypt passwords utilizing the default hard-coded seed worth for the older variations.”
The attackers behind the second incident appear to have been extra expert and used extra superior reconnaissance techniques. They enumerated area trusts by utilizing nltest instructions they usually collected details about native and area administrative accounts by utilizing instructions resembling localgroup, web consumer, web consumer /area and ID. Additionally they tried to find community configuration, time logs, and question consumer info.
In line with CISA the attackers tried to repeat and exfiltrate system registry hives resembling HKEY_LOCAL_MACHINE (HKLM) and the Safety Account Supervisor (SAM), however the exercise was detected and blocked. “The SAM Registry file could enable for malicious actors to acquire usernames and reverse engineer passwords; nonetheless, no artifacts had been accessible to substantiate that the menace actors had been profitable in exfiltrating the SAM Registry hive,” the company stated.
The attackers additionally dumped the reminiscence of the native safety authority subsystem service (LSASS), which often comprises NTLM credentials for consumer accounts that had been used on the system, together with disabled credentials that may nonetheless be legitimate on different methods.