A cold boot attack is when an attacker analyses the data in RAM before it is gone. Obscurix is vulnerable to these as it does not currently have a way to wipe the data in RAM at shutdown.
After you have shutdown Obscurix, if an attacker manages to take your RAM sticks and analyse the data in them then they may be able to see exactly what you've been doing. Data in RAM usually disappears a few minutes after shutdown but if they are cooled (e.g. by putting them inside a refridgerator), then the data can last up to a few hours.
If you think cold boot attacks will be a problem for you, then guard your computer for a few minutes after shutdown to ensure nobody has access to your RAM. You can also solder the RAM sticks into your motherboard to make it harder for them to be seized. If using a laptop, take out the battery and run directly off the charging cable and pull out the cable after shutdown to ensure the RAM has no access to more power to stay alive.