Neosploit update and changes

Some interesting changes we have observed:

- URL scheme changed
- Javascript deobfuscation updated
- Vulnerabilities exploited changed

Javascript deobfuscation code has changed a bit. Previously, to get to the actual exploit code one had to go through two decryption stages, this time an additional stage is added to the very first layer. This additional layer does not make a request out to the server.

Basically, upon first visit to the Neosploit site a browser gets one big obfuscated Javascript page. It executes the decryption function which results in another obfuscated javascript layer. This second layer decrypts itself and then runs real javascript of the first stage. This stage adds some encoded parameters to the URL for the second stage.

URL scheme for requests to exploits and binaries has been updated. It appears that a full structure is passed as a parameter to the main script. This struct is hex encoded as a string and uses various flags and variables to track victims and statistics.

Javascript decryption function utilizes the "arguments.callee" trick to convert itself into an uppercase string and use offsets within this string to decrypt the payload. This is the main deobfuscation characteristic of Neosploit. Several changes have been made previously which break down the methods into seperate variables instead of using them directly.

An interesting addition has been included recently, which appends Neosploit's web address to the decoding offset string. Thus, to successfully decrypt the payload the original full address of the script must be known. Also, at the exploit stage there's a function which sets a unique cookie ("ID") with a specific value for a given exploit.

Stage 1

First stage is the initial visit (iframe, redirect, ...) to Neosploit page. At this point a structure is created based on public variables such as the User Agent string and IP address. Then the server returns obfuscated Javascript page, which is dynamically generated with random variables, and contains the first part of the URL for the next stage.

Stage 2

This stage is obfuscated with two layers and then attempts to identify the victim's Service Pack level, and system's language then builds a request string with these parameters to get the second stage. This request URL has a specific argument to the main script. First part is added by the server upon initial visit and consists of various hashed parameters then SP level and language string is appended.

Stage 3
Deobfuscation yields the exploit code for the following vulnerabilities (in exploit order):

- CVE-2006-0003 ; MS06-014 ; MDAC (BD96C556-65A3-11D0-983A-00C04FC29E36)
- CVE-2006-5820 ; "Sb.SuperBuddy.LinkSBIcons()" ; Cookie ID = 9
- CVE-2007-5779 ; "GomWebCtrl.GomManager.1.OpenURL()" ; Cookie ID = 13
- CVE-2008-1472 ; CA BrightStor ArcServe Backup AddColumn() (BF6EFFF3-4558-4C4C-ADAF-A87891C5F3A3) ; Cookie ID = 21
- CVE-????-???? ; "QuickTime.QuickTime.4" ; Cookie ID = 6

PS: Symantec stated that recent Adobe vulnerability was being exploited by this toolkit, however the instance which was analyzed for this post did not include any Adobe exploits.

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