Here is an update to my Python templates (binary and text files).
I’ll explain the updates to each template in upcoming blog posts.
python-templates_V0_0_2.zip (https)
MD5: 082812485D24AD0E3D12F1618BC44367
SHA256: 98DE8BEC508C7E678D294DD630466DA175524D4180C1E8C3A6C06EE11587981E
This update for translate.py, a tool to “Translate bytes according to a Python expression”, adds a new function for XOR multy-byte-key encoding/decoding.
translate_v2_5_7.zip (https)
MD5: 886C1B4C518EA58F972F87980994B976
SHA256: 01E4239E050DE4853AC53020CCE44C9804003A4A2C195974B5B16AEDD1B8E1B1
This new version of format-bytes.py brings a new option when extracting bitstreams: producing a stream of 0s & 1s, like this:
Join specifier j:b (option “-f bitstream=…”) produces a bitstream of 0s & 1s, that I can then process further:
The png file I analyze in this example, was created with PHP Stegger on the Geocaching Toolbox site.
format-bytes_V0_0_13.zip (https)
MD5: E7A7A344B3B8753553FC5B2E4084D8DA
SHA256: 1F22A1D784DCF1269FFD12E2C9467EE0FB93B0895CC24D04CBBD9696D50945DB
This version of hex-to-bin.py, a simple tool to convert hexadecimal data to binary, can also handle bitstreams (option -b) with this update. If necessary, the bitstream is right-padded with 0s to make the bitstream length a multiple of 8.
Example:
hex-to-bin_V0_0_4.zip (https)
MD5: CBD3D27A2BC703F51FB23F757084BBE1
SHA256: CD70D7644BB353C64DD37AA0717B14967176A1A5E35E5DC6AE163D929BE13AAD
This new version of xmldump.py, a tool to parse and display xml content, has a new command: pretty.
As its name implies, this command performs a pretty print of the xml content.
xmldump_V0_0_4.zip (https)
MD5: A97F4048226BD9A0BE47D1ABDEC5D770
SHA256: 2636D10294C5BCD8B1E97DFE30745FF91496FB9F87ABB8D99371B379AA711B25
This new version of oledump.py has a feature to display Ad Hoc YARA rules using option –verbose.
In this example, I show a string Ad Hoc YARA rule to search for string attri (-y #s#attri). By including option –verbose, the YARA rule generated by oledump for string attri is displayed first:
Plugin plugin_http_heuristics has a new option: -c –contains.
By default, plugin_http_heuristics looks for (obfuscated) strings that start with keywords (http:// and https:// by default). Option -c changes this behavior: when this option is used, the keywords are searched in the entire string, and not just at the start.
In this example, I use this feature to search for the filename of the dropped executable (strings containing “.exe”):
And I also include plugin_vba: this is an old plugin that I failed to release. It searches for string concatenation in VBA code.
Video:
oledump_V0_0_45.zip (https)
MD5: FB9694358CCEAE4AFDFCF97FDA0D5205
SHA256: FB75B1E19E5067751E2DE1AD21826245B7E11EDBE03278566484754F606F3965
This is a Python 3 bug fix version for pecheck.py, a tool to analyze PE files.
pecheck-v0_7_9.zip (https)
MD5: F69709C475D513A8D2031C21EEC13284
SHA256: 99E71A9FC917BB27CDD893F14AE77F2E810A4C7BB56A6E975BB619C978B12D47
Here is an overview of content I published in January:
Blog posts:
YouTube videos:
Videoblog posts:
SANS ISC Diary entries:
You can start a packet capture on a vanilla Windows machine with command “netsh trace start capture=yes” (and end it with “netsh trace stop”).
This packet capture file, with extension .etl, can not be opened with Wireshark. Until recently, I used Microsoft’s Message Analyzer, but this tool is no longer supported and installation files have been removed from Microsoft’s site.
In comes etl2pcapng, a new open-source utility from Microsoft that converts an .etl file to .pcapng format:
“Utility that converts an .etl file containing a Windows network packet capture into .pcapng format“.
I contributed to version 1.3.0 of etl2pcapng, by adding a comment containing the Process ID to each packet. etl files contain metadata (like the PID of the process associated with the network traffic) that got lost when translating to pcapng format. As the pcapng format has no option to store the PID for each packet, but it supports packet comments, I stored the PID inside packet comments:
Notice this warning by Microsoft:
The output pcapng file will have a comment on each packet indicating the PID of the current process when the packet was logged. WARNING: this is frequently not the same as the actual PID of the process which caused the packet to be sent or to which the packet was delivered, since the packet capture provider often runs in a DPC (which runs in an arbitrary process). The user should keep this in mind when using the PID information.
In this new version of hash.py, a tool to calculate hashes, I add “hash” checksum8.
Checksum8 calculates the sum of all bytes contained in the provided file(s), each byte is interpreted as an unsigned, 8-bit integer.
I recently had to validate that the path of a URL was a “valid” Meterpreter identifier. When the least significant byte of the 8-bit checksum of the path is equal to 92 (0x5C), then we have a valid URL for a Windows Meterpreter stager.
Take this URL: http://127.0.0.1/RVdP. Could this be a “Windows Meterpreter” URL? Let’s calculate the checksum of RVdP:
The 8-bit checksum of RVdP is 0x015C. The least significant byte is 0x5C, or 92: this matches URI_CHECKSUM_INITW, e.g. this could indeed be a URL used by a reverse http Meterpreter payload.
Besides this new feature, hash.py comes with other features like “pack expressions” and various bug fixes.
hash_V0_0_8.zip (https)
MD5: 03F928332874447F6198A9FDE46E3AA7
SHA256: 80C493639CA7160D1455FABA38A2A04556240326D4BA78B8207CA8FF8B09E1B2
Didier Stevens 