7 Minute Security

Happy Friday! Today’s another hot pile of pentest pwnage. To make it easy on myself I’m going to share the whole narrative that I wrote up for someone else: I was on a pentest where a DA account would sweep the networks every few minutes over SMB and hit my box. But SMB signing was on literally everywhere. The fine folks here recommended I try relaying to something NOT SMB, like MSSQL. This article had good context on that: https://www.guidepointsecurity.com/blog/beyond-the-basics-exploring-uncommon-ntlm-relay-attack-techniques/. I relayed the DA account to a SQL box that BloodHound said had a “session” from another DA. One part I can’t explain is the first relay got me a shell in the context of NT SERVICE\MSSQLSERVER. That shell broke for some reason while I was sleeping that night, and the next relay landed as NT AUTHORITY\SYSTEM (!). The net command would let me add a new user, but BLOCK me trying to make that new user a local admin. However, a scheduled task did the trick: xp_cmdshell schtasks /create /tn