Monday, July 14, 2008

Malware and Office Documents Joining Forces

Common office files as documents, presentations, spreadsheets and PDF files, are the most widely abused ones in targeted attacks, which when backed up with enough personal information and take into consideration the time of their attack if the social engineering campaign is either going to be based on a current/upcoming event, or on an event anticipated due to information gathered through open source intelligence, often make it through common signature based scanning solutions.

Despite the relatively easy to obtain, point'n'click DIY tools for backdooring common office files are available for the script kiddies to take advantage of, some are naturally remaining proprietary tools, making them harder to analyze unless a copy is obtained. Like this one, generating "undetected" by signatures based scanning, office documents and spreadsheets that would drop the actual malware on the PC.

Automatic translation of its description and core features :

"The program represents a generator macros in the language Visual Basic for Application (VBA), for introduction in the document Microsoft Office Word / Microsoft Office Excel executable file (win32 exe), followed by fully automatic recovery and launch, without any  additional action by the user. The only requirement that formed in such a way xls / doc files is to support  VBA macros on the computer end-user formed file and permission to launch macros.

The program uses NOT a vulnerability (exploit) or macro-virus tools for the introduction, extraction or running embedded files. This means that it has generated macros compatible with ALL versions of Microsoft Office products starting with Microsoft Office 97 package, with any established "patches" and the service pack. Macros generated by this program not detected antivirus, for the simple reason that they are not viruses or macro viruses. The program uses only "established" means products built into Microsoft Excel VBA language to achieve their goals.

- Fully automatic generation of macro for the introduction of documents word / excel any given exe-file with his persistence in the body and subsequent documents automatic recovery and launch, when opening a document word / excel. 

- Generated macros are compatible with all versions of ms word / excel since version 97,  employments and regardless of the presence / absence of any patches / servicepacs. 

- Generated macros are not macro-viruses, exploits do not use and do not contain any malicious code, so do not be detected by any antivirus tools as viruses. 

- Conversion body ex-file macro happening in such a way that while in doc / xls file it not detected any antivirus, and can be freely sent by mail safely passed all checks, even if in itself contains viral code defined antivirus.


- Sgenerirovanny and attached to the body of the document macro can be protected with a password or signed certificate, using funds established Microsoft Office, which does not affect him productivity or efficiency (macro, in any case remain fully workable). 

- Box macro can be made both in the new document, and in any document containing data and-or other macros. Generated program code is fully compatible with any other embedded in the document macros or entering data, and will not interfere with their work, as well as maintain its efficiency.

- Added auto-finding ways to extract exe-file;

- Added possibility of a macro arbitrary text in the body of the instrument;

- Optimized algorithm macro-generation code;

Enabling this option will lead to the creation macro code, who himself will find a way to unpack and run embedded exe-file. Auto-search finds the current user folder and produces there extraction and launch embedded file. The peculiarity of this method is that this method will work on the computers of users with a limited account, because in its user folder in any case has the right to record / performance. Using this option is justified to improve the "punching" macro on computers with limited account or unknown file structure (let Windows installed on the disk is different from C).

You can specify a name for final file independently, or leave blank, then the name will be generated automatically.

On this possibility has asked for a user program, its essence is that after running a macro, retrieval and downloading exe-file the document with the introduction of exe-file will be withdrawn posed text. Perhaps in this way can improve the application of social engineering, designed to force the user to allow support for macros. For example, in the text of the document indicate:

"This document contains hidden text (password, a system of calculation formulas, interactive components, etc.), Which can be viewed only after the inclusion of support macros. Please enable support for macros and re-opening this document ".

After resolving support macros, and the implementation of embedded exe-file, the document will be withdrawn given a string containing probable "password" or any other textual information.

Despite that the tool is proprietary, the underground economy's leaks are largely driven by bargain hunters who would exchange proprietary tool, whose often biased exclusiveness may increase the profit margins, for a service or a good that may be worthless for them in general, but impossible to obtain and take advantage of in the present. It will not just leak in one way or another, someone will inevitably backdoor the backdooring tool and trick the novice bargain hunters into running it, by having both their host infected and money taken.

Related posts:

The Underground Economy's Supply of Goods and Services

Yet Another DIY Proprietary Malware Builder

The Small Pack Web Malware Exploitation Kit - Proprietary

DIY Exploit Embedding Tool - A Proprietary Release

Skype Spamming Tool in the Wild - Proprietary Release

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