NETRESEC Network Security Blog - Tag : keyword
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)
A new function in the free version of CapLoader 1.2 is the "Find Keyword" feature. This keyword search functionality makes it possible to seek large capture files for a string or byte pattern super fast!
You might say, so what? PCAP string search can already be done with tools like tcpflow, ngrep and even Wireshark; what's the benefit of adding yet another tool to this list? One benefit is that CapLoader doesn't just give you the packet or content that matched the keyword, it will instead extract the whole TCP or UDP flow that contained the match. CapLoader also supports many different encodings, which is demonstrated in this blog post.
Here are a few quick wins with CapLoader's keyword search feature:
- Track User-Agent - Search for a specific user agent string to extract all the HTTP traffic from a particular browser or malware.
- Track Domain Name - Search for a particular domain name to get all DNS lookups as well as web traffic relating to that domain (including HTTP "referer" field matches).
- Extract Messages - Search for a keyword in e-mail or chat traffic to get the whole e-mail or conversation, not just the single packet that matched.
- Extract Files - Search for a unique string or byte sequence in a file (such as a piece of malware) to enable extraction of the complete file transfer.
EXAMPLE: DigitalCorpora M57
As an example, let's search the digital corpora file net-2009-12-06-11:59.pcap (149 MB) for the keyword "immortal". Follow these steps in order to veify our analysis using the free edition of CapLoader.
Start CapLoader and select File -> Open URL, enter:
- Edit -> Find Keyword (or Ctrl+F), enter "immortal"
- Click the "Find and Select All Matching Flows" button
- One TCP flow is now selected (Flow_ID 5469, 192.168.1.104:2592 -> 192.168.1.1:25)
- Right click the selected flow (ID 5469) and select "Flow Transcript"
CapLoader transcript of SMTP email flowLooks as if an email has been sent with an attachment named "microscope1.jpg". However, the string "immortal" cannot be seen anywhere in the transcript view. The match that CapLoader found was actually in the contents of the attachment, which has been base64 encoded in the SMTP transfer in accordance with RFC 2045 (MIME).
The email attachment can easily be extracted from the PCAP file using NetworkMiner. However, to keep things transparent, let's just do a simple manual verification of the matched data. The first three lines of the email attachment are:
/9j/4AAQSkZJRgABAQEAkACQAAD/2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBDecoding this with base64 gives us:
0000000: ffd8 ffe0 0010 4a46 4946 0001 0101 0090 ......JFIF......
0000010: 0090 0000 ffdb 0043 0001 0101 0101 0101 .......C........
0000020: 0101 0101 0101 0101 0101 0101 0101 0101 ................
0000030: 0101 0101 0101 0101 0101 0101 0101 0101 ................
0000040: 0101 0101 0101 0101 0101 0101 0101 0101 ................
0000050: 0101 0101 0101 0101 01ff db00 4301 0101 ............C...
0000060: 0101 0101 0101 0101 0101 0101 0101 0101 ................
0000070: 0101 0101 0101 0101 0101 0101 0101 0101 ................
0000080: 7061 7373 776f 7264 3d69 6d6d 6f72 7461 password=immorta
0000090: 6c01 0101 0101 0101 0101 0101 0101 ffc0 l...............
Tools like ngrep, tcpflow and Wireshark won't find any match for the string "immortal" since they don't support searching in base64 encoded data. CapLoader, on the other hand, supports lots of encodings.
Supported Text Encodings
CapLoader currently supports fast searching of text strings in any of the following encodings:
- Base64 (used in email attachments and HTTP POST's)
- DNS label encoding (RFC 1035)
- Quoted Printable (used in body of email messages)
- URL encoding
CapLoader also supports several local character sets, including the following code pages:
- 437 MS-DOS Latin US
- 850 MS-DOS Latin 1
- 932 Japanese
- 936 Simplified Chinese
- 949 Korean
- 1251 Windows Cyrillic (Slavic)
- 1256 Windows Arabic
Having all these encodings also makes it possible to search network traffic for words like хакер, القراصنة, ハッカー, 黑客 or 해커.
CapLoader is a commercial tool that also comes in a free trial edition. The search feature is available in both versions, so feel free to download CapLoader and try it your self!
CapLoader is available from the following URL:
Posted by Erik Hjelmvik on Wednesday, 02 April 2014 13:15:00 (UTC/GMT)