Wednesday, August 05, 2009

Spam or not?

Whenever I receive any "interesting" spam, I have the habit of investigating and tracking down the sender and trying to analyze the motivation of the sender. This email caught my attention in the same way.

See the email for yourself.

Yes, that is all it had. My initial reaction was that, the hacker sender was a amateur so he didn't know how to make the mail look legitimate -- but not for so long, when I discover that this email was totally legitimate and was indeed sent by Standard Chartered Bank - SCB (Unless!! : read the epilogue of this post).

Ok, let's go through the email. The email is poorly formatted (maybe spam?). The only useful content is the 'Click here' link and it points to something like eh8IBgAGA19XRAwETAA6XweWkKK (more and more like spam). I clicked on this link, and I was taken to a page that looked exactly like SCB's site; it didn't take me long, before I figured out that the page was actually the real SCB inet banking login page, and not a fake one!! I verified the SSL certificates and they are valid, trusted and belong to SCB (Thanks to the further confirmation from Firefox that it said I had visited this site more than 100 times earlier -- 100 is just an illustration, don't try to guess anything). At this point, I had no answer. If that was a spam, why would I be redirected to the bank's page; and if it was not a spam, why would a bank send such a suspicious email and redirect to a login page through a third-part link??!!! Instead of speculating, I thought I would analyze the technical aspects of this email first.

Given that the link didn't point directly to the bank's site (but to, I first verified if (see the from address of the email) belongs to SCB. It turned out that is legitimate and registered against SCB's head office in Hong Kong. Now that is valid, I verified the email headers to check if the email was indeed sent from '' domain. The email had come from an MX from and the return path is to Now, it makes sense why the link was pointing back to At this moment, I thought it was a spam originating from But when I digged out more details, I was shocked. belongs to a legitimate email service provider registered in Mumbai. When I went through their customer lists, I started to believe that this email is legitimate -- all of its customers are well known institutions in India including a handful of banks (Interestingly, SCB is not listed as one of them). But a list of customers of this grade, made me believe that an email from would not be a spam.

One last thing I still wanted was, to take a look at how the redirection from to SCB's inetbanking site happens -- just to ensure if there is any injection of any XSS stuff. I did a wget on the given URL, just returns an HTTP error code 302 (meaning Moved Temporarily) and redirects to the SCB's legitimate page. This was a clean redirection and this solves the last question, and the sender has no "hacking" benefit out of this.

After all this, I finally believed that this mail was legitimate and not a spam. I am really depressed with the kind of security implications that such an email would cause. If a legitimate institution can send a spam-like email, why wouldn't it be easy for a spammer to send a legitimate-like email and deceive the user??!!

I still "wish" this to be a spam (I just can't believe a bank would do this!!); If it was a spam, the only benefit for the sender that I can "speculate" is: Maybe the sender is tracking the number of users who actually click on this link and navigate. Maybe the sender would send a number of such legitimate messages, and then suddenly a phishing email, so the user doesn't realize the difference and gets trapped. I can't think of anything else.

Any other thoughts?

If you enjoyed reading this analysis, you might also be interested in my analysis of another interesting spam I received.

Disclaimer: I've no confirmation from SCB that it is legitimate email. So it could still be a spam. Use your own conscience and decide it for yourself.


  1. Man.... do u have some free time or do u have some free time :D

    jokes apart.. very interesting .. hmmmm....

  2. it is not about 'free' time, but about interest. :) Security is a domain by itself.

  3. >> If a legitimate institution can send a spam-like email, why wouldn't it be easy for a spammer to send a legitimate-like email and deceive the user??! <<

    Loved this quote :-)))

  4. Hey this is simple. The mail you got was outsourced. And the link was redirected , so that it can be tracked. This is called click-tracking

  5. @techblogged: Hey, I'm not wondering about the reason for their re-direction; but from security perspective, it is unacceptable to trust a third party to redirect to a banking site. Just wrong! The email is a clear clone of a typical spam, but in reality it is not! that's the point here.

  6. One guess. The mailserv has many legitimate customers but not SC. So, it could be an attempt to cause some damage to SC by sending spam emails to its customers. Isn't it true that the more the spam from a bank the more threatened are its customers?

  7. I don't clearly understand what you mean. I assume you say that someone wanted to spoil the reputation of the bank, by sending spam from That shouldn't be possible because, is a legitimate mail service provider and they should take care of their clients' authenticity.