I've recently spoke with a couple of analysts I know, and during the course of these conversations, I was somewhat taken aback by how little seems to be known or available with respect to Jump Lists. Jump Lists are artifacts that are new to Windows 7 (...not new as of Vista...), and are also available in Windows 8. This apparent lack of attention to Jump Lists is most likely due to the fact that many analysts simply haven't encountered Windows 7 systems, or that Jump Lists haven't played a significant role in their examinations. I would suggest, however, that any examination that includes analysis of user activity on a system will likely see some significant benefit from understanding and analyzing Jump Lists.
I thought what I'd try do is consolidate some information on Jump Lists and analysis techniques in one location, rather than having it spread out all over. I should also note that I have a section on Jump Lists in the upcoming book, Windows Forensic Analysis 3/e, but keep in mind that one of the things about writing books is that once you're done, you have more time to conduct research...which means that the information in the book may not be nearly as comprehensive as what has been developed since I wrote that section.
In order to develop a better understanding of these artifacts, I wrote some code to parse these files. This code consists of two Perl modules, one for parsing the basic structure of the *.automaticDestinations-ms Jump List files, and the other to parse LNK streams. These modules not only provide a great deal of flexibility with respect to what data is parsed and how it can be displayed (TLN format, CSV, table, dumped into a SQLite database, etc.), but also the depth to which the data parsing can be performed.
Jump List Analysis
I thought what I'd try do is consolidate some information on Jump Lists and analysis techniques in one location, rather than having it spread out all over. I should also note that I have a section on Jump Lists in the upcoming book, Windows Forensic Analysis 3/e, but keep in mind that one of the things about writing books is that once you're done, you have more time to conduct research...which means that the information in the book may not be nearly as comprehensive as what has been developed since I wrote that section.
In order to develop a better understanding of these artifacts, I wrote some code to parse these files. This code consists of two Perl modules, one for parsing the basic structure of the *.automaticDestinations-ms Jump List files, and the other to parse LNK streams. These modules not only provide a great deal of flexibility with respect to what data is parsed and how it can be displayed (TLN format, CSV, table, dumped into a SQLite database, etc.), but also the depth to which the data parsing can be performed.
Jump List Analysis
The custom Jump Lists (*.customDestinations-ms files located in %UserProfile%\AppData\Roaming\Microsoft\Windows\Recent\CustomDestinations) are created when a user "pins" an item (see this video for an example of how to pin an item). The *.customDestinations-ms files are apparently just a series of LNK format streams appended to each other.
Each of the Jump List file names starts with a long string of characters that is the application ID, or "AppID", that identifies the specific application (and in some cases, version) used to access specific files or resources. There is a list of AppIDs on the ForensicsWiki, as well as one on the ForensicArtifacts site.
From an analysis perspective, the existence of automatic Jump Lists is an indication of user activity on the system, and in particular interaction via the shell (Windows Explorer being the default shell). This interaction can be via the keyboard/console, or via RDP. Jump Lists have been found to persist after an application has been deleted, and can therefore provide an indication of the use of a particular application (and version of that application), well after the user has removed it from the system. Jump Lists can also provide indications of access to specific files and resources (removable devices, network shares).
Further, the binary structure of the automatic Jump Lists provides access to additional time stamp information. For example, the structures for the compound binary file directory entries contain fields for creation and modification times for the storage object; while writing and testing code for parsing Jump Lists, I have only seen the creation dates populated.
Digging Deeper: LNK Analysis
Within the automatic Jump List files, all but one of the streams (i.e., the DestList stream) are comprised of LNK streams. That's right...the various numbered streams are comprised of binary streams following the MS-SHLLINK binary format. As such, you can either use something like MiTeC's SSV to view and extract the individual streams, and then use an LNK viewer to view the contents of each stream, or you can use Mark Woan's JumpLister to view and extract the contents of each stream (including the DestList stream). The numbered streams do not have specific MAC times associated with them (beyond time stamps embedded in MS-CFB format structures), but they do contain MAC time stamps associated with the target file.
Most any analyst who has done LNK file analysis is aware of the wealth of information contained in these files/streams. My own testing has shown that various applications populate these streams with different contents. One thing that's of interest...particularly since it was pointed out in Harry Parsonage's The Meaning of LIFE paper...is that some LNK streams (I say "some" because I haven't seen all possible variations of Jump Lists yet, only a few...) contain ExtraData (defined in the binary specfication), including a TrackerDataBlock. This structure contains a machineID (name of the system), as well as two "Droids", each of which consists a VolumeID GUID and a version 1 UUID (ObjectID). These structures are used by the Link Tracking Service; the first applies to the new volume (where the target file resides now), and the second applies to the birth volume (where the target file was when the LNK stream was created). As demonstrated in Harry's paper, this information can be used to determine if a file was moved or copied; however, this analysis is dependent upon the LNK stream being created prior to the action taking place. The code that I wrote extracts and parses these values into their components, so that checks can be written to automatically determine if the target file was moved or copied.
There's something specific that I wanted to point out here that has to do with LNK and Jump List analysis. The format specification for the ObjectID found in the TrackerDataBlock is based on UUID version 1, defined in RFC 4122. Parsing the second half of the "droid" should provide a node identifier in the last 6 bytes of stream. Most analysts simply seem to think that this is the MAC address (or a MAC address) for the system on which the target file was found. However, there is nothing that I've found thus far that states emphatically that it MUST be the MAC address; rather, all of the resources I've found indicate that this value can be a MAC address. Given that a system's MAC address is not stored in the Registry by default, analysis of an acquired image makes this value difficult to verify. As such, I think that it's very important to point out that while this value can be a MAC address, there is nothing to specifically and emphatically state that it must be a MAC address.
DestList Stream
The DestList stream is found only in the automatic Jump Lists, and does not follow the MS-SHLLINK binary format (go here to see the publicly documented structure of this stream). Thanks to testing performed by Jimmy Weg, it appears that not only is the DestList stream a most-recently-used/most-frequently-used (MRU/MFU) list, but some applications (such as Windows Media Player) appear to be moving their MRU lists to Jump Lists, rather than continuing to use the Registry. As such, the DestList streams can be a very valuable component of timeline analysis.
What this means is that the DestList stream can be parsed to see when a file was most recently accessed. Unlike Prefetch files, Jump Lists do not appear (at this point) to contain a counter of how many times a particular file (MSWord document, AVI movie file, etc.) was accessed or viewed, but you may be able to determine previous times that a file was accessed by parsing the appropriate Jump List file found in Volume Shadow Copies.
Summary
Organizations are moving away from Windows XP and performing enterprise-wide rollouts of Windows 7. More and more, analysts will encounter Windows 7 (and before too long, Windows 8) systems, and need to be aware of the new artifacts available for analysis. Jump Lists can hold a wealth of information, and understanding these artifacts can provide the analyst with a great deal of clarity and context.
Resources
ForensicsWiki: Jump Lists
Jump List Analysis pt. I, II, III
DestList stream structure documented
Harry Parsonage's The Meaning of LIFE paper - a MUST READ for anyone conducting LNK analysis
RFC 4122 - UUID description; sec 4.1.2 describes the structure format found in Harry's paper; section 4.1.6 describes how the Node field is populated
Perl UUID::Tiny module - Excellent source of information for parsing version 1 UUIDs
轉自 http://windowsir.blogspot.com/2011/12/jump-list-analysis.html
發表文章
0 意見: