Showing posts with label plain text. Show all posts
Showing posts with label plain text. Show all posts

Tuesday, 21 June 2016

Citrix's GoToMyPc users exposed after password leak



If you are a user of Citrix's GoToMyPC unfortunately you will have to reset your passwords (use something long varied and strong, don't reuse an old password!).

The service, which lets users remotely access PCs over the internet, was hit by a "very sophisticated password attack," Citrix said Sunday in a blog post. The company is requiring users to reset their passwords using the "forgot password" link. This is just another hack in a long line that have been disclosed in the past few weeks as hackers seem to be targeting website with huge user databases in an attempt to reap the rewards of cybercrime.

"Citrix takes the safety and security of its customers very seriously, and is aware of the password attack on GoToMyPC," said John Bennett, product line director at Citrix, in a statement. "Once Citrix learned about the attack, it took immediate action to protect customers. Citrix can confirm the recent incident was a password re-use attack, where attackers used usernames and passwords leaked from other websites to access the accounts of GoToMyPC users. Further, there is no indication of compromise to any other Citrix product line."

To reset your GoToMyPC password, go to the site and click on the Log In link.
I would recommend along with resetting your password that you enable two-step verification, a process that sends a code to your phone each time you want to sign in. If you've used the same password for GoToMyPC at other websites or for other accounts, you should change it at those places as well and don't make up a new password and use it on your other sites to, not that you would do such a thing.

Monday, 11 April 2016

Unlock files infected by Petya Ransomware


As many people are well aware ransomware has spread through the internet like a wild bush fire encrypting millions of machines across the world. The good news if any is that researchers have broken the petya strain of this plague. This mean that if your machine has been encrypted by this particular strain then you are in luck, don't pay any money over to these criminals get a tech savvy friend and do the following. Download this tool created by Leostone that  exploits a mistake made by Petya's author in the way that the ransomware encrypts a file on a Windows machine, opening opportunities for the decryption key to be determined. To use the decryption tool you will need to attach the Petya affected drive to another computer and extract specific data from it hence why I said get a tech savvy friend. The data that needs to be extracted is 512-bytes starting at sector 55 (0x37h) with an offset of 0 and the 8 byte nonce from sector 54 (0x36) offset: 33 (0x21). This data then needs to be converted to Base64 encoding and used on the petya pay no ransom site to generate the key.

As luck would have it security researcher Fabian Wosar has developed a "Petya Sector Extractor that can collect the specific data needed to use Leostone's tool. All a user needs to do is load up their hard drive on an uninfected Windows computer and run Wosar's solution.
After copying and pasting the information generated by the Petya Sector Extractor, victims can then use Leostone's tool to generate a decryption key. That key will decrypt the victim's infected files once the hard drive has been once again loaded into the infected computer. If you have been infected by other strains of ransomware check out some of my past posts to check if there is a crack available that you can utilize. Until next time all I can say is "think before you click".



Tuesday, 9 February 2016

Recovering "Deleted" snapchat messages


You have just arrived at this post and read the heading "recovering deleted snapchat messages" and now your thinking snapchat deletes my messages after 10 seconds doesn't it? Well the simple answer to that question is no. This isn't any kind of a new revelation the research has been around since 2013 it just doesn't seem to be well known so I have decided to do my part to try and highlight it. The main reason for writing this post is to try and get the message through to teenagers and young adults that the content you are sending may not be secure and could come back to bite you. There is also a massive legal issue with the sending of explicit images if both parties are seen as minors and you could land yourself in a whole lot of trouble with the law. It is important to presume that anything you send or do online can be traced and made public so the safest approach to take is think twice before sending anything out there that may prove harmful to yourself or others.

If you would like to read through the report on how to recover snapchat messages and I suggest that you do the link can be accessed here. After reading this report maybe you might consider sending a snap to your friends just to let them know you have a code red situation and you need to meet up. For anyone who is to lazy to click on the link I have copied in the body of the report below.
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Methodology

We used two android devices to examine artifacts left behind by Snapchat. An account (rhickman1989) was created on a Samsung Galaxy Note 2, and pictures and videos were sent to another account (DeciphForensics). The receiving account was logged into on a Samsung Galaxy S3, when some of the images and videos were viewed, while others were not. We then acquired the phone using AccessData’s Mobile Phone Examiner+ version 5.2.1.499. After the acquisition was complete, the image was exported as an .AD1 image file, and then imported to AccessData’s Forensic Toolkit version 4.0.2.33.
After a brief examination of the contents, a different account (decipforensics2) was created on the Samsung Galaxy Note 2, and more pictures and videos were sent to the account on the Samsung Galaxy S3 (rhickman1989). This was to determine if there are identifiers for the sender account of a “snap.” The same acquisition process was followed again after the second batch of “snaps” were sent.
After another brief examination of the contents, pictures and videos were sent from the Samsung Galaxy S3 with the rhickman1989 account to both the DeciphForensics and DecipForensics2 accounts. The same acquisition process was followed again after sending these “snaps.”
All examination took place using AccessData’s Forensic Toolkit version 4.0.2.33.

Snapchat Structure

The majority of Snapchat data is stored within the data/data/com.snapchat.android folder. There are four folders within this directory, with two folders within the cache folder.
Examination of the Samsung Galaxy S3 revealed that within the shared_prefs folder are several XML files: CameraPreviewActivity.xml, com.google.android.gcm.xml, com.snapchat.android_preferences.xml, and SnapPreviewActivity.xml.

The com.snapchat.android_preferences.xml File

This file is where the majority of information stored by Snapchat is located. Within this file is a listing of all the contacts stored on the device. This is done with the permission allowed by the user for the application to read the contacts on the device.
Below the list of contacts is a listing of Snapchat messages. It appears that there is a set of fields stored for each message in Snapchat. The following are the fields stored in this section of the XML file: type, mSender, mWasViewed, mCaptionPosition, mCaptionOrientation, mIsLoading, mIsTimerRunning, mIsBeingViewed, MWasOpened, mWasScreenshotted, mDisplayTime, mId, mTimestamp, mStatus, mIcon, and mMediaType.
We sent only two pictures from the DecipForensics2 account, and one was viewed and expired. Within this XML file are two records that show the mSender field set to “decipforensics2.” Of those two records, one has the mWasOpened set to “true.” The author kept documentation as to which images were opened and allowed to expire and which are not, so it is known which image is tied to this record.
The mTimestamp field is stored in Epoch format. Upon conversion of this value, it showed the time that the image was either taken or viewed. Further research will need to be done to determine which it is, however, the time is within the timeframe of both being sent and viewed. Unfortunately, the author did this within a few minutes of each other and did not record the exact time sent.
The mId field for the picture shown to the left is “270518365528484358r.” The mTimestamp field in the same record is “1365528484358.” After converting the Epoch time format to readable format, the time stamp is for April 9, 2013 11:28:04 MDT. The similarities here will be address further in a later section of this paper

The received_image_snaps Folder

Within this folder were located every image sent to the DeciphForensics account on the Samsung Galaxy S3, including the images that had been viewed and were expired. There were some duplicate images with different names as well, the reason for this is unknown.
Android developers created a way for media files such as graphics to be stored on the phone for application use and function without being put into the Gallery application as an image to be viewed. The way that they did this was with .nomedia files. “If a directory has a file named .nomedia, then the media store will not scan and record the metadata of files in that directory” (Hoog, 2011).
Each of the images within the received_image_snaps folder had a .nomedia extension appended to the end of the file name. For example, the name of the file figure 3 is “h1a81hurcs00h1365528700423.jpg.nomedia”. This was likely done to prevent the images stored within this directory from being placed in the gallery or from being scanned by the media store. AccessData’s Forensic Toolkit recognized the .nomedia extension that was appended to the end of the file name and ignored it, displaying the images.

Correlations between the XML Records and the Image Names

There is a small correlation between records within the com.snapchat.android_preferences.xml file and the name of the image file stored in the received_image_snaps folder.
As shown above, there are three correlations between the name of the image, the mTimestamp value, and the mId value. While this is consistent with this image, it is not always consistent with all images. The section in blue is present in several of the other images, only with different numbers following to separate the image.

Conclusion

The author began this research in an attempt to answer several vital questions about the Snapchat application as it is stored and used on Android devices. The author has concluded that metadata is stored for Snapchat images, as shown by the com.snapchat.android_preferences.xml file, and that it contains metadata about expired “snaps” as well as unexpired “snaps,” and that images that are sent via Snapchat are indeed recoverable, and do not “disappear forever.”





Tuesday, 8 December 2015

Protecting Windows 10 (The Basics)



Over the past few months Microsoft have been firing out their new operating system Windows 10 to the world for free. This blog is more aimed at anyone who is just after installing the operating system as chances are if you are a windows user you may have already upgraded or will be doing so in the near future. Like most things that come fresh out of the box to make them work to a level you might expect takes some tweaking. I am going to focus on a few basic steps you should take right away to make your new operating system secure.

1) Run the windows update straight away, I know you may have spend an hour or two installing the dam thing but running windows update will make sure your operating system has the latest patches. To find windows update just click the little search bar at the bottom of your screen and type "windows update" once opened just hit "check for updates" and your done.

2) System restore is turned off by default in Windows 10 so you might want to turn this on. Microsoft have renamed this function as "system protection" so to turn this on head back down to the little search bar and type "This PC" when the logo appears right click on it and select "Properties" click on "system protection" then click "Configure" and turn system protection on.

3) Check your Windows 10 privacy setting by default everything and I mean everything in here is turned on. To get here you go to START > Settings> Privacy spend a bit of time looking over this and make sure you are happy with it.

4) Make sure that all of your applications are updated in an earlier post I mentioned that Secunia PSI was a good application to check this.

5) Make sure you have your anti-virus turned on if you don't have an anti-virus Windows has a build in AV called Windows Defender. You can find Defender by going to the search bar and typing "Windows Defender".