I was being troubled by the error:
The InstallShield Engine (iKernel.exe) could not be launched.
The RPC Server is unavailable.

If you start the service “DCOM Server Process Launcher” you should be able to do away with this error.

I wanted to install Cisco VPN client on BackTrack3. You can get the Cisco VPN client source using the following command:
wget ftp://ftp.cs.cornell.edu/pub/rvr/upload/vpnclient-linux-4.8.00.0490-k9.tar.gz
tar zxvf vpnclient-linux-4.8.00.0490-k9.tar.gz
cd vpnclient/
wget http://tuxx-home.at/projects/cisco-vpnclient/vpnclient-linux-2.6.22.diff
patch < vpnclient-linux-2.6.22.diff
./vpn_install

I got this information from the following blog.
I ran into an error whereby the kernel sources were not found for the VPN client to install. I then got the BackTrack3 kernel sources.
cd /lib/
wget http://www.offensive-security.com/kernel.lzm
mkdir test
lzm2dir kernel.lzm test

Now go into the vpnclient directory and execute the following:
./vpn_install

Accept the defaults (except in my case I selected “No” on automatically start VPN client). When it asks for the sources point it to:
/lib/test/usr/src/linux-2.6.21.5

Then the VPN Client should compile without any issues. Then you just need to place your Cisco VPN client Profile (.pcf) in the /etc/opt/cisco-vpnclient/Profiles directory. You will need to first start the VPN client service first using:

/etc/init.d/vpnclient_init start

Once the service is started just connect using:

vpnclient connect mypcffile user test password <whatever>

Please note that the full name of the Profile file in the above case is mypcffile.pcf but I’ve deliberately excluded the .pcf extension.
This should work.

I wanted to have a list of all the security conferences around the world for a quick reference so I compiled together a list.

I think Nmap is by far the best portscanner around if you want to do some serious port-scanning. Nmap performs a DNS resolution by default. This is good for obtaining the fully qualified domain names (FQDN), however, in some cases when you are scanning huge networks spanning several class Bs, it can have a significant effect on the duration of the scan.
Although using the -n parameter can completely stop nmap from performing any resolutions, but sometimes there’s that fine granularity that you need, i.e., you want to perform name resolutions but not if it exceeds a certain amount of time. I have to say that I wouldn’t have even craved for such an idiosyncratic feature, had it not been for nmap. Fyodor has been awesome enough to provide fine-grained control over port-scanning to your heart’s content.
So I opened up the nmap code, trying to figure out if I could fine tune that feature myself and I was not at all surprised that there were several comments in the code that would give you the impression that the authors of nmap have been considering this feature.
At this time it seems that the timeouts for the DNS servers are being read out of an arrayname:
static int read_timeouts[][] in nmap_dns.cc.
The way the code works is, this array has retransmission timeouts. Each row of this array represents what retransmission timeouts that nmap will follow depending on the number of DNS servers provided.

In nmap 4.76, therefore, if you specify one DNS server (or only one entry exists in /etc/resolv.conf) nmap will wait 4000ms, then another 4000ms followed by 5000ms before giving up. But if you do specify two DNS servers, then for the first DNS server the timeouts are 2500ms followed by 4000ms and then the same is tried for the 2nd entry in the DNS servers. Therefore, it seems that nmap will wait 13 seconds at max before giving up on the DNS resolution of a host. Imagine scanning a class B and having to wait 13 seconds for each of the hosts to resolve. It would be a significant overhead.

Of course, one can find other things to do if the IP address space is not DHCP, e.g., starting a separate list scan (-sL) and a portscan (with -n) simultaneously so that the DNS resolution timeouts do not result in a major impact as far as the portscanning itself is concerned.
There could be pros and cons to this as well which I may have failed to consider. But at this time it seems that it might be the most judicious approach.

I’ve been waiting for a good writeable NTFS file system. I used Captive-NTFS but wasn’t really happy with it. Lots of errors when I used it last in July – August 2006 (if I remember the timeline correctly). Now we have a great writeable NTFS file system for Linux called NTFS-3g.

On my Kubuntu machine, I installed it as:
sudo apt-get install ntfs-3g
I also installed ntfsprogs available from http://packages.debian.org/unstable/otherosfs/ntfsprogs for my Kubuntu machine. The use for the NTFS-Progs is that you can use utils like ntfs fix if your mounted NTFS is tainted. If you do not have a latest version installed of ntfs-progs you might run into issues where ntfsfix might not work. Use the latest version from the above link. You might need to install libntfs9 from the debian package as
dpkg -i libntfs9_1.13.1-6+b2_i386.deb
Now I was getting tired of having to unount my NTFS partitions first and then re-mount them in ntfs-3g mode to make them writeable. So I installed ntfs-config and also the patched pmount debian package. Then all you have to do is run ntfs-config and choose the option that suits you best.
Now all my USB drives that have NTFS on it mount in read/write mode!

I was just browsing away when I stumbled upon Johnny Long’s GooScan. He says that this is a Linux only tool but it seems to compile (not without problems though) on cygwin.
I kept getting the following errors:

L:\tools\gooscan-v1.0.9>gcc gooscan.c
gooscan.c: In function `inet_send':
gooscan.c:575: error: `MSG_WAITALL' undeclared (first 
                       use in this function)
gooscan.c:575: error: (Each undeclared identifier is 
                       reported only once
gooscan.c:575: error: for each function it appears in.)

Then I read somewhere that MSG_WAITALL is not defined for Cygwin and that instead of that zero would work. There are many neater solutions to this…but I’m a hacker and I’ll do the stuff that’s easiest and hassle-free.
Some people say that the following will work:
#ifdef __CYGWIN__
#define MSG_WAITALL 0

So in order to compile this bad boy, you need to goto line 574 in your favorite editor.
It looks like this:
recv(sock, recvbuf, sizeof(recvbuf), MSG_WAITALL);

You need to make it look like this:
recv(sock, recvbuf, sizeof(recvbuf), 0);//MSG_WAITALL);

You are all set:
gcc gooscan.c -o gooscan.exe

Compilation works! But then I observed that the results were not coming well. However, if you run it through a local proxy such as burp it still works…I bet it has something to do with socket establishment and receiving and being incompatible with the MSG_WAITALL flag.
But as long as you can get the results … who cares? If someone figures out exactly how to make this work, please post it as a comment.

9 hrs down the line I’m still capturing packets, now comes the challenging part-to make the hash tables of raw data! My Rabin’s hash algo seems to be working but the only hiccup that could happen was when the negative hash values are obtained. I don’t know whether it is a bug in my code or what but I got negative values for Rabin’s Hash when I gave the string “this is test”! This is gonna test me for sure.