Anti-Ransomware

A counter-action of last blog :
The password for unlocking hijacked-files by Ransomware are widely available online now.

One nature of encryption is that there is a one-to-one match of general used encryption softwares/tools. When a hacker distribute his ransomware to the victim, there is one key for encrypting files. There is also one key to unlock these files.

Each release of ransomware will share the same unlocking key and this is the weakness of ransomware. When the password is publicly available, the ransomware is useless.

However, there maybe multiple releases with different keys. In such case, the hacker will need to keep track of which key corresponding which release. The logistics maybe overwhleming.

One direction of development is there is a pattern of generating keys (like using a master key and the username, ip address or computer service patch number). Then the variant of keys of each releases will be multiplied.

Comments

Post a Comment

Popular posts from this blog

Risk on Radio

This morning I joined a talk show on RTHK and discussed risk of usnig credit cards. Media attendtion is high after the recent security breach at Cardsystems. The story was uncovered on 17 June 2005, but after 6 days it is still lingering on. WHY? First, I believe this incident is huge in terms of people affected. 40 million card numbers were lost. Secondly, it was uncovered on SAT. I am not joking. One of my lectures in a Crisis Management class told his student in class that when reporters are hungry for news, even lost of a penny can be headline news. On Saturday, when reporters unable to find new story, a incident like this one will be reported by every newspaper. Back to the talk show, there were few people called in. And one mentioned that when he visited a Indian online shop and was diverted to a HSBC credit card website. This website asked him to enter his personal information like birthday and passport number. He worried this may be fraudulent website and asked for advice. As
Read more

Root Certificate update and software design

Recently, a member of PISA (also called Anthony) noticed that when using HK Post office website, FireFox displayed security warning saying the digital certificate used bu HK Post is invalid. A detailed study by other PISA members showed that the reason HK Post (once is the root CA for HK) used their own root certificate. Root certificates are usually shipped with the browser installation and HK Post digital certificate was not included in their default software package. Hong Kong Post setup a page to teach users on how to add the root certificate to most used browsers . However, how many users know this link, willing to follow or could follow the instructions !! It is quite clear that currently most browsers develop and distributed by US company or US-based community. The interest of adding other root certificates is likely lower than adding new functions. Having said that, FireFox developers have a process to add Root Certificates to their software package, for example this li
Read more

One source of poverty

A study focused on the effects of Wal-Mart stores on poverty rates found that an estimated 20,000 families nationwide have fallen below the official poverty line as a result of the chain's expansion. Although I have not read the whole report nor the article confirmed the research method is scientific, I agree with the author that "found that one of the greatest effects of a Wal-Mart opening is the closing of mom-and-pop-type operations."
Read more