Script Kitties Early Trick or Treat, Part 2

I promised a treat. Well, as scripts go, this will probably be like the time you went trick-or-treating as a kid and the old couple gave you three pennies and then you walked down the street and realized the pennies seemed to smell bad, but hey, it's money you didn't have before, so what the hay. It's not quite that bad, it's just I wrote it in 2006 and I didn't do much to bring it into modern times. But, here we go...

In 2006, PowerShell was just about to be released and around the same time I was thinking, darn it, wouldn't it be easier to experiment with VBScript if they had given me a command line? So I made one.

As it turns out, some malware is written in VBScript, so this came in handy a while back for me to decode a few lazily "encoded" strings that were assembled using the VBScript Chr() function and string concatenation. It let me figure out what COM objects were being created and move on with my life, so maybe it'll be useful to you.

I also added the ability to switch to JScript, because people also write malware in JScript, so hell, why not.

Here's a little demo:

You're wishing I just gave you the pennies now, aren't you.

Yeah, that's it. If you look at the code, you'll find out why it stinks just like those pennies. But it serves its purpose. So, enjoy!

Here's the code: https://github.com/strictlymike/eval-hta

Script Kitties Early Trick or Treat, Part 1

Some of my old sysadmin tricks became useful again when I analyzed some malware targeting Windows Scripting Host (WSH). In this article I'll share a trick, and in the next, I'll share a treat.

When logic gets hairy, both developers and malware analysts open a debugger to get more information. But what can be done when the target platform is WSH? As it happens, there are debuggers for this, too, and they can be had by installing either Microsoft Office or Microsoft Visual Studio in your dynamic analysis VM. To invoke the debugger, use the /X switch of either cscript.exe or wscript.exe, e.g.:

wscript.exe /X rat3ie.vbs

Here's the Visual Studio debugger, halting on line 1 of a craptacular VBScript RAT:

This gives the ability to view local variables in the Locals tab (at bottom), set breakpoints, and step through code.

That's all for this little nugget. Next time, I'll post a tool I wrote in 2006 that came in handy for conveniently and interactively evaluating VBScript and JScript to de-obfuscate strings and experiment with malware functionality.

"Advanced" OllyDbg Scripting

Alternative possibilities:

• I'm daft;
• OllyDbg's "Warn when breakpoint is outside the code section" option can't (always?) be truly disabled in odbg110; or,
• This is not the droid (i.e. option) that I'm looking for.

In any case:

Set sh = CreateObject("WScript.Shell")

While True
    Call sh.SendKeys("%Y")
    Call WScript.Sleep(100)
Wend

And goodbye to this dialog when attempting to find the OEP by tracing into:

Next episode, we answer the question: did OllyDump ever finish? ;-)

Edit 10/14/2016: It never finished, so I ended up doing it manually by catching the unpacker in a memcpy and dumping its payload from poi(esp+4). You live, you learn.