Solved

Doc, Xls, and Pdfs act like they are corrupt on desktop

Posted on 2014-01-09
7
474 Views
Last Modified: 2014-01-15
A user has several folders on their win 7 desktop that contain pdfs, doc, docx, and xls files. When we try to open them it says they are corrupt. Any files of the same extention that are saved in other locations on the HD do not say this. Can you help?
0
Comment
Question by:portillosjohn
  • 4
  • 3
7 Comments
 

Author Comment

by:portillosjohn
ID: 39768239
On closer inspection it is all docs and docs on the computer. I have already scanned with malware bytes and eset and it finds nothing.
0
 
LVL 62

Expert Comment

by:☠ MASQ ☠
ID: 39770254
Check JPEGs as well.  If it's all Office files and common image formats this is Cryptolocker.

An Offline scan should find the infective component which is hidden while active on the machine.  If the infection was Cryptolocker then you've almost certainly lost the data :(

See: http://www.experts-exchange.com/Security/Encryption/Q_28295419.html
0
 

Author Comment

by:portillosjohn
ID: 39771371
Its not all the jpegs. Just one folder on the destkop. I can't find any evidence that it is cryptolocker. Plus no ransom message.
0
Why You Should Analyze Threat Actor TTPs

After years of analyzing threat actor behavior, it’s become clear that at any given time there are specific tactics, techniques, and procedures (TTPs) that are particularly prevalent. By analyzing and understanding these TTPs, you can dramatically enhance your security program.

 
LVL 62

Expert Comment

by:☠ MASQ ☠
ID: 39771837
Are the only files affected in the one folder or is it just JPEGs in one folder that are affected?

Check your eset logs to see if anything has been removed or quarantined recently
0
 

Author Comment

by:portillosjohn
ID: 39771919
It seems to be only JPEGs in one folder that are affected. The logs came up blank as well...Really wierd.
0
 
LVL 62

Accepted Solution

by:
☠ MASQ ☠ earned 500 total points
ID: 39771967
If you're certain the system is clean I'd still suspect you're looking at ransomware damage - you won't get a message on the screen until all the indexed files are encrypted so if the payload was removed by AV or anti-malware tools only some files will be affected and the damage becomes apparent.  These nasties tend to index the HDD and then work their way sequentially through the file structure so look to see if the locations could be indexed in order. you may find a folder that's only part encrypted which is the point at which the damage was stopped.  

The lack of a cleanup log indexing a ransomware signature undermines this but the pattern of Office files and JPEGs is consistent with that kind of infection.
0
 

Author Closing Comment

by:portillosjohn
ID: 39782587
Looks like it was the cryptolock. The user had backups which he did not tell me at the start......
0

Featured Post

What Is Threat Intelligence?

Threat intelligence is often discussed, but rarely understood. Starting with a precise definition, along with clear business goals, is essential.

Join & Write a Comment

No matter the version of Windows you are using, you may have some problems with Windows Search running too slow or possibly not running at all. Before jumping into how you can solve this issue, just know there are many other viable alternative deskt…
This article will guide you to convert a grid from a picture into Excel format using Microsoft OneNote and no other 3rd party application.
The viewer will learn how to make their project stand out over others by learning how to change colors and shapes, add spaces, change directions, and add bullets to their charts.
Learn how to make your own table of contents in Microsoft Word using paragraph styles and the automatic table of contents tool. We'll be using the paragraph styles in Word’s Home toolbar to help you create a table of contents. Type out your initial …

747 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

10 Experts available now in Live!

Get 1:1 Help Now