The DNS Z flag is bit within the DNS protocol header that is, per the IETF design, meant to be used reserved (unused).
Although recently it has been used in DNSSec, the value being set to anything other than 0 should be rare.
Otherwise if it is set to non 0 and DNSSec is being used, then excluding the legitimate domains is low effort and high reward.
Determine if multiple of these files were accessed in a short period of time to further enhance the possibility of seeing if this was a one off or the possibility of larger sensitive file gathering.
This Sigma query is designed to accompany the Corelight Threat Hunting Guide, which can be found here: https://www3.corelight.com/corelights-introductory-guide-to-threat-hunting-with-zeek-bro-logs'
Detects the exploitation of OMIGOD (CVE-2021-38647) which allows remote execute (RCE) commands as root with just a single unauthenticated HTTP request.
Verify, successful, exploitation by viewing the HTTP client (request) body to see what was passed to the server (using PCAP).
Within the client body is where the code execution would occur. Additionally, check the endpoint logs to see if suspicious commands or activity occurred within the timeframe of this HTTP request.
NKN is a networking service using blockchain technology to support a decentralized network of peers. While there are legitimate uses for it, it can also be used as a C2 channel. This rule looks for a DNS request to the ma>
detects execution of psexec or paexec with renamed service name, this rule helps to filter out the noise if psexec is used for legit purposes or if attacker uses a different psexec client other than sysinternal one
Detects usage of the windows RPC library Encrypting File System Remote Protocol (MS-EFSRPC). Variations of this RPC are used within the attack refereed to as PetitPotam.
The usage of this RPC function should be rare if ever used at all.
Thus usage of this function is uncommon enough that any usage of this RPC function should warrant further investigation to determine if it is legitimate.
View surrounding logs (within a few minutes before and after) from the Source IP to. Logs from from the Source IP would include dce_rpc, smb_mapping, smb_files, rdp, ntlm, kerberos, etc..'
Detects the remote installation of a print driver which is possible indication of the exploitation of PrintNightmare (CVE-2021-1675).
The occurrence of print drivers being installed remotely via RPC functions should be rare, as print drivers are normally installed locally and or through group policy.