[Zeek-Dev] Zeek DCE-RPC Analyzer Update

Gabriele Pippi g.pippi at certego.net
Thu Sep 19 09:10:11 PDT 2019

Zeek-Dev Group,

hi i'm Gabriele from purple team of Certego. We are trying to rely on zeek
to increase the detection of our platform in the *moving** through the
internal network sc*enario ( *credential access*, *discovery* and
specially *lateral
movement* ATT&CK Matrix phases).

In the case of dcerpc for the moment we are correlating the information
generated by *bro_dce_rpc *parser with data coming from endpoint agents.

In order to reduce the number of false positives and to gather more
detailed information for a possible analysis, we thought it would be really
interesting "to get extensive parsing in place for DCE-RPC messages by
parsing the IDL files [...]" or to implement a "byte string containing the
stub data itself" in case it is not encrypted. In our case we would like to
give priority to all those operations that allow to directly carry out an
entire attack or a code execution, restricting the scope to those with stub
data in cleartext (for example in the case of dcerpc over smb named_pipe or
in the case of dcom, at least for the operations observed until now ). I
found the following BINPAC
*zeek/src/analyzer/protocol/dce-rpc/endpoint-atsvc.pac*, and I ended up to
this discussion

*Have there been any updates regarding this topic? Do you have any advice
on how to proceed?*

Once we have assessed the feasibility, we could be willing to contribute to
achieve this goal. In this work we would also like to insert a series of
endpoints and operations that currently are not mapped by zeek, among those
observed for example there are several in DCOM. Once the tests are
completed, if you are interested, we could also provide you with an
exhaustive list or integrate it directly with a possible merge.

At the moment we do not know of the existence of technologies that allow to
do alerting on some types of *Windows APIs*, we therefore believe that
being able to do it at the network level through DCERPC is an important
added value to zeek.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.icsi.berkeley.edu/pipermail/zeek-dev/attachments/20190919/1e522e04/attachment.html 

More information about the zeek-dev mailing list