recover pictures from corrupt memory card

If you took some unique photos and then your photo camera starts acting strangely, telling you something about "no pictures", "file corrupt", "no card inserted" or similiar errors, or if you realize it later when coping on your PC, that images files are corrupt, there might be a way to save your pics. When you google, you'll find lots of expensive commercial programs.

PhotoRec is an excellent command line freeware running on all major operating systems.

I successfully retrieved all photos of a corrupt xD-Card.

It may be also used to generally recover data from corrupt media!

thanks and credits to Christophe Grenier

retrieve passwords of connected WLAN and dialup networks

When you visit a friend and need his internet, he gives you access to his PC but doesn't necessarily know where to look up the data to make you use the internet from your own laptop.

If you have physical access to a PC, you still cannot get the WLAN password or the DSL dial-up info, since they are not displayed as clear text but as stars.

Excellent little freeware tools let you do it on windows, assuming you kindly asked your friend, or you forgot your own passwords:

Wirelesskeyview shows you the password of currently connected WLAN networks on the PC you run it on.

Dialuppass shows you complete access codes of active DSL/dial-up connections on the PC you run it on.

Ironically: since you retrieve passwords, some antivirus software detects the downloaded program as trojan ("false positive" problematic). Of course I can't guarantee anything, but i didn't get any trojan.

thanks and credits to Nir Sofer

recover password of open-protected PDFs

Today i needed to review several lectures PDF but they were password protected and i lost the password. If you have no other means to get the password somewhere, there are two programs that allow to open it anyway, with some patience:

One expensive commercial one and the commandline opensource program: PDFcrack.

It is primarily available for linux, but there exist a windows version bundled with the required cygwin library.

According to the pdfcrack FAQ, depending on your country, use of the software is NOT necessarily illegal!

It took me about 3 hours to crack a simple 5 letter password, however this depends on the encryption used.

If you remember that the password was let's say longer than i.e. 4 characters, you can save lots of time by evoking the command like this: pdfcrack -n 5.

The software is not multithreaded, but you can speed up things on multicore processors by running two instances i.e. one with -n 5 and one with -n 7 parameter. However, monitor the length of the "current word" from time to time, to avoid that the same work is done twice.

thanks and credits for pdfcrack go to Henning Noren

EDIT: I found an extended pdfcrack allowing multithreading for multicore systems.

EDIT 2: 40bit encrypted pdf are ok but if it's a 128bit, be warned: you need a looot of time...

presentation

Hello,

in this blog i want to archive useful little findings of technical nature, which resolve practical problems and which often are not well known