Daniel Bernegger

HACKVent 2020 – Day 11

Challenge – Chris’mas carol

Since yesterday’s challenge seems to have been a bit on the hard side, we’re adding a small musical innuendo to relax.

My friend Chris from Florida sent me this score. Enjoy! Is this what you call postmodern?…

HACKVent 2020 – Day 6

Challenge – Twelve steps of christmas

On the sixth day of Christmas my true love sent to me…

six valid QRs,
five potential scrambles,
four orientation bottom and right,
and the rest has been said previously.

PDF version


a printer




Since I am not that much into rubik cubes, I tried the brute force method.…

HACKVent 2020 – Day 5

Challenge – Image DNA

Santa has thousands of Christmas balls in stock. They all look the same, but he can still tell them apart. Can you see the difference?


The first attempt so solving the challenge was to load the images into an editor and inspect them visually.…

HACKVent 2020 – Day 3

Challenge – Packed gifts

One of the elves has unfortunately added a password to the last presents delivery and we cannot open it. The elf has taken a few days off after all the stress of the last weeks and is not available.…

HACKVent 2020 – Day 2

Challenge – Chinese Animals

I’ve received this note from a friend, who is a Chinese CTF player:


Unfortunately, Google Translate wasn’t of much help: 

I suspect the data has somehow been messed up while transmitting it.

Sadly, I can’t ask my friend about more details.

HACKvent 2020 – Day 1

Challenge – Happy HACKvent 2020

Welcome to this year’s HACKvent.

Attached you can find the “Official” invitation to the HackVent.

One of my very young Cyber Elves cut some parts of the card with his alpha scissors.

Have a great HACKvent,

– Santa


Those alpha scissors are clearly a hint.…

HACKVent 2020

HACKVent is hacking-labs advent calendar, with a hacking (or “capture the flag”) challenge a day.

The challenges in the beginning are rather easy, but get more complicated and time consuming each day.

Since the CTF-challenges are still in progress, our write-ups will only be released after HACKVent ends, so don’t expect the links to work before January 1st, possibly later.…

Exchange 2010 Logs Eating Up Storage Space

The Microsoft Exchange Server 2010 writes all processes – before it enters them into its database – in “transaction logs”. From these logs, the entire database can therefore be reconstructed in the event of damage. But I don’t want to go into this in detail – if you are interested in this, you can read more about it here: link. The real problem is that these logs can eat a lot of memory over time. Read here how to free it.

Read More »Exchange 2010 Logs Eating Up Storage Space