Apr 10 2020 09:19 AM
Apr 10 2020 09:19 AM
I have deployed a Minemeld server in Azure, I'm pulling free threat intel in there. Processing it, then using the Microsoft Security Graph extension to forward it to Microsoft. Turned the Threat Intel Connector on and now I have the Threat Intel in the LogAnalytics space.
There are two issues I have, in order:
1. Currently, with threat intel of type IP, I get the IP in a field called ExternalIndicatorID. A sample value for this is: IPv4:18.104.22.168-22.214.171.124 . As you can see, we have IPv4: then a range of IPs follows. The problem is this is something that's very impractical to use from an analytics point of view. I have to write the query in such a way to ignore the "IPv4:" and then also be able to interpret range. This is impractical and the preview Threat Intel rules offered by Microsoft do not use that field. They instead use NetworkIP, NetworkDestinationIP, NetworkSourceIP ....whichever of the three they find with a value. For me however, those values are empty.
Apparently this is something that must be changed with the Minemeld processor so that it does not merge IPs and generate ranges. I have not found a way to do that.
Has anyone managed to do that or otherwise any other workarounds to be able to consume Minemeld IP Threat Intel in Sentinel?
2. The second thing and I'm not completely sure here as nr 1 was a much bigger priority, is the Microsoft Security Graph extension for Minemeld only able to consume URLs, Domains and IPs? No emails, hashes, etc?
I have also asked on Palo Alto's board, however I'm really curious and could use a hand from someone who managed to already do this.
Apr 13 2020 01:12 AM
Is it possible to remove the "IPv4" bit when you ingest the data through the Graph API? I assume you are using some kind of scripts? I think it will be the easiest to remove it that way.
Security Graph supports the following TI's:
- Network (IP address, CIDR block, URL)
More information can be found here.
Apr 13 2020 01:17 AM
The data is getting to the Graph via an Mimemeld extension provided by them here https://github.com/PaloAltoNetworks/minemeld-msgraph-secapi.git
The how to can be found here https://live.paloaltonetworks.com/t5/MineMeld-Articles/Send-IOCs-to-Microsoft-Graph-API-With-MineMel...
You are saying to remove the IPv4 bit after ingestion by the Graph?
Also that would only be part of the problem. There is still the IP range that is problematic to interpret in KQL.
Apr 13 2020 11:12 PM
May 15 2020 08:19 AM
By any chance is there any solution for this. I just integrated Minemeld with Azure Sentinel and see the similar issue of getting range of IP address which will not help us to identify from which single IP the actual threat is
May 19 2020 03:24 AM
@pavankemi nope, will likely be done at query time in Sentinel. Please let me know if you find any other workarounds.
I've checked the python code and it seems like it SHOULD provide single ips, not ranges. No idea how to solve this.
Oct 01 2020 09:02 AM
Hi Gary, the TI queries join the SigninLogs or AzureActivity tables with TI using IP address so I don't understand how to use ipv4_is_match() in this scenario.
Oct 02 2020 04:28 AM
@JoachimLassus Take a look at parse_ipv4_mask(). You would need to use it to convert you IP addresses into the long number and then do the comparison in your query. It will also take some string manipulation to get the format that you need (you would think the command would be written to do all of that for you already).
Oct 05 2020 06:56 AM
Sorry which bit isn't working? https://docs.microsoft.com/en-us/azure/data-explorer/kusto/query/parse-ipv4-maskfunction this will work from any Workspace that Azure Sentinel is associated with. However you will need a record in the Workspace that has a IP and prefix mask to supply as a parameter:
SigninLogs | summarize by IPAddress, parse_ipv4_mask(IPAddress,31)
Oct 05 2020 07:29 AM
ThreatIntelligenceIndicator | extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP) | where isnotempty( TI_ipEntity) //| project NetworkIP = "126.96.36.199/31" | extend TI_ipEntity = iif(NetworkIP has "/", tostring(split(NetworkIP,"/").),NetworkIP) | project TI_ipEntity, NetworkIP | join ( SigninLogs //| project IPAddress = "188.8.131.52" ) on $left.TI_ipEntity == $right.IPAddress | project IPAddress, NetworkIP | extend NetworkIP = iif(NetworkIP has "/", tostring(split(NetworkIP,"/").),NetworkIP) | project parse_ipv4_mask(IPAddress, toint(NetworkIP))
You can probably check for a IP with a prefix mask "/" and filter those, something like the above?
Oct 05 2020 09:14 AM
Ah ok, my entries in that column are empty, so it could work like this? Checking each TI entry against the Signinlogs
ThreatIntelligenceIndicator //| where isnotempty(NetworkCidrBlock) | project NetworkCidrBlock = "184.108.40.206/26" | project justIP = tostring(split(NetworkCidrBlock,"/").) , prefixIP = toint(split(NetworkCidrBlock,"/").) | join ( SigninLogs | project IPAddress = "220.127.116.11" ) on $left.justIP == $right.IPAddress | project parse_ipv4_mask(justIP, prefixIP)
You'll need to uncomment line 2 and remove lines 3 & 7
ThreatIntelligenceIndicator | where isnotempty(NetworkCidrBlock) //| project NetworkCidrBlock = "18.104.22.168/26" | project justIP = tostring(split(NetworkCidrBlock,"/").) , prefixIP = toint(split(NetworkCidrBlock,"/").) | join ( SigninLogs //| project IPAddress = "22.214.171.124" ) on $left.justIP == $right.IPAddress | project parse_ipv4_mask(justIP, prefixIP)
Oct 06 2020 03:06 AM
Thanks for you response, correct me if I'm wrong but I believe that query only considers if 126.96.36.199 exists in the Signinlogs.
188.8.131.52/24 would give you a range of 184.108.40.206 - 220.127.116.11 so if someone with IP 18.104.22.168 signs in it wouldn't trigger an alert.