NETRESEC Network Security Blog - Tag : IP
We are happy to announce the release of CapLoader 1.7!
Here’s an overview of what’s new in this release:
- Regular expression searching
- Lookup of IP addresses using online services
- Lookup of domain names using online services
- Improved protocol fingerprinting speed and precision
- Support for GRE, IGMP and ICMPv6 flows
- More precise period estimation of “periodic services”
Regular Expressions Search
CapLoader’s “Find Keyword” window has been extended with an option to search flows using regular expressions (regex) as an alternative to searching for strings or byte sequences. With help of the powerful regex syntax built into .NET this new search option enables very flexible searching.
Image: Searching for Alfa Ransomware flows using regex
The Find Keyword window can be opened by clicking Edit > Find Keyword, or by pressing
You can learn more about regex searching with CapLoader in our short video called "Detecting the Pony Trojan with RegEx using CapLoader".
OSINT Lookups of IP Addresses and Domains
We added support for querying online services for IPs and domain names to the latest release of NetworkMiner, now it’s time to add this very handy feature to CapLoader as well.
Right-clicking a Flow, Service or Host in CapLoader brings up a context menu with links to various online resources that might have more details regarding the clicked IP address or domain name.
The services available for IP address OSINT lookup include:
APNIC Whois, Censys, Cymon, ExoneraTor, Google Public DNS, GreenSnow.co, Hurricane Electric, IBM X-Force, Internet Storm Center, mnemonic Passive DNS, PacketTotal, SecurityTrails, Shodan, ThreatCrowd, ThreatMiner, UrlQuery and VirusTotal.
The domain name lookup menu contains a similar set of providers:
Cymon, Google Public DNS, Google Safe Browsing, Hybrid Analysis, IBM X-Force Exchange, mnemonic Passive DNS, MXToolBox, MyWOT, Norton Safe Web, PacketTotal, SecurityTrails, ThreatCrowd, ThreatMiner, URL Void, UrlQuery, VirusTotal, Website Informer, Webutation and Whoisology.
The dynamic protocol detection (or Port Independent Protocol Detection, aka “PIPI”) in CapLoader has been improved to support even more protocols than before. We have also fine-tuned the protocol identification algorithm to be both faster and more accurate.
Image: Traffic to TCP 8777 identified as SSL (PCAP file from Stratosphere IPS)
Updating to the Latest Release
Users who have previously purchased a license for CapLoader can download a free update to version 1.7 from our customer portal. All others can download a free 30 day trial from the CapLoader product page (no registration required).
We’d like to thank Michael Nilsson for suggesting the IP and domain name lookup feature and Tohar Braun for suggesting RegEx search support. We’d also like to thank Ralf Alvarsson and Jarmo Lahtiranta for reporting bugs that have been resolved in this release.
Posted by Erik Hjelmvik on Tuesday, 03 July 2018 11:37:00 (UTC/GMT)
CapLoader comes with support for Berkeley Packet Filter (BPF), which makes it possible to filter network traffic based on IP addresses, protocols and port numbers without using external tools. Being able to filter captured network traffic is crucial when analyzing large sets of PCAP files as well as in order to hunt down compromised hosts with Rinse Repeat Intrusion Detection.
There are two ways to apply filters with BPF in CapLoader; you can either apply an input filter before loading your PCAPs, or you can apply a display filter after the capture files have been loaded.
The fastest way to filter a large set of PCAP files with CapLoader is to enter an Input Filter before loading the capture files. Having an input filter will speed up the loading time significantly, since CapLoader will not need to analyze packets and flows that don't match the BPF syntax. The downside is that you will need to know beforehand what filter you want to use. In order to apply a changed input filter you need to reload the loaded PCAP files (pressing F5 will do this for you).
Image: CapLoader with input filter “tcp port 443”
CapLoader supports display filters in order to allow filters to be changed on the fly, without having to reload the PCAP files. As the name implies, display filters affect what flows/services/hosts that are displayed in CapLoader. A changed display filter does not require the dataset to be reloaded, but it does require the GUI to update the visible flows. This GUI update will be somewhat slower compared to when setting an input filter.
Image: CapLoader with display filter “host 22.214.171.124”
CapLoader's BPF implementation does not support the full BPF syntax. In fact, only the most central primitives are implemented, which are:
|host <IP address>||Flows to or from the specified IPv4 or IPv6 address|
|net <CIDR>||Flows to or from the specified IP network, uses CIDR notation|
|port <port>||Flows to or from the specified port number|
|ip6||Flows using IPv6 addresses|
|ip||Flows using IPv4 addresses|
More complex filter expressions can be built up by using the words and, or, not and parentheses to combine primitives. Here are some examples:
- host 126.96.36.199 and udp port 53
- net 188.8.131.52/22 and port 80
- (port 80 or port 443) and not host 192.168.0.1
For all boolean algebra geeks out there we can confirm that our BPF implementation gives and precedence over or, which means that the last example above would give a different result if the parentheses were removed.
Keeping it Short
Steve McCanne gave a keynote presentation at SharkFest 2011, where he talked about how he created BPF. Steve's work was guided by Van Jacobson, who challenged him to make the BPF syntax human friendly rather than requiring the user to type a clunky filtering syntax. We've adopted this thinking and therefore allow filters like these:
Flows to or from IP address 10.1.1.3. Translates to “ip host 10.1.1.3”
Flows to or from the 184.108.40.206/16 network. Translates to “ip net 220.127.116.11/16”
- port 53
Flows to or from TCP, UDP or SCTP port 53.
Try it for Free!
We've made the BPF implementation available even in the free version of CapLoader. You don't need to register to get the free version; just download, extract and run. The tool is portable, so you won't even have to install it. Visit https://www.netresec.com/?page=CapLoader to grab a copy and start filtering!
With the release of CapLoader 1.4 it is now possible to apply Display Filters not only to the Flows tab, but also to the Services and Hosts tab.
Posted by Erik Hjelmvik on Monday, 30 November 2015 08:15:00 (UTC/GMT)