Showing posts with label spam. Show all posts
Showing posts with label spam. Show all posts

5/8/08

Backscattered?

Are you seeing a bunch of email bounces in your inbox - bounces from emails that you never sent in the first place?

For example:

From: Some System Administrator
Undeliverable
Subject: Your message "Swanky Rolex Watches" could not be delivered
Error 1234; see attached for details

I am.

Fortunately, it (probably) doesn't mean that somebody has hijacked your email account and is sending email as you, getting rich from selling swanky Rolex knockoffs. There's always a chance your email account has been hijacked, no matter how remote; however there is NO chance anybody's getting rich on swanky Rolex fakes. Is there? Hmm...does anybody really buy fake Rolex watches, besides maybe duped characters in sitcoms which of course aren't real people (except for The Simpsons). Or maybe costume designers for TV and movies? Which I assume has to be a very narrow market. But I digress.

It's called backscattter or "collateral spam," and unfortunately it's the next wave of trouble we can expect from email on the internet.

Backscatter is a message you receive, informing you that email you did not send was not delivered to someone you do not know. Spammers or viruses send out mail forging your email address in a the reply-to, knowing that it will get blocked by anti-spam firewalls. (Note that this is different than hijacking your account - hijacking means that somebody has real access to your email, sending messages through our own network surreptitiously. That's a far worse situation).

Spammers are banking on the fact that there are so many improperly configured mail servers and firewalls which will accept those messages and generate Non-Delivery Reports (NDRs, or bounces) to the forged address in the reply-to. That's you.

So, this is an indirect way of sending spam, relying on social engineering. I'm sure a lot of people see these "Message could not be delivered" emails and open them - after all, it could have been an important email you sent which never got delivered. But instead you've just been tricked into opening spam.

And these messages pass a lot of firewall test because they're non-delivery reports. The email subject line itself generally doesn't contain anything which looks like spam, and the actual message is often contained as an attachment.

For now, all you can do is grin and bear it - and keep hitting the delete key. If you want to learn more about this subject, have at it here or here.

4/3/08

Phishing, Spam Increase. Sigh.

Holy cow has spam been annoying lately. Don’t know about you, but mine’s up by at least 10%. I’m seeing a lot of phishing-based spam, too - the kind that tries to get you to “update your account info now.” Today I’ve seen three or four claiming to be from Wells Fargo.

Yes, Wells Fargo is ever-so-nice and helpful, giving me this chance to help them “ensure the integrity and security of our online banking system.” The email claims that they tried to contact me by phone, but were unable to - hence this convenient email with a link to my account information. You know, just so I can review it and make sure it is right.

I think I’ve touched on this before, but one can never be too careful. First, banks and doctors and insurance companies and so forth will almost never, ever communicate with you this way. If there is something to be updated, you’ll probably learn of it via your postal mail communications (a note on your bill or statement, for example) or AFTER logging into their online system. Also, typos and strange grammar are dead-giveaways. Finally - check out the full message header and see where the email really comes from. In Apple Mail, select the message from your message list and then go to View / Message / Long Headers.

I didn’t even need to do that for this Wells Fargo spam/phish. The perp didn’t even bother changing the “Reply To,” which is arbitrary and set to anything you like. It’s “akstcabcaccountancymnsdgs@abcaccountancy.nl” - pretty far removed from WellsFargo.com, don’t you think?

Finally, keep in mind that a lot of times phishers and spammers will use what's called "social engineering" to try to get you to do unsafe things online. This time of year, we're likely to see a lot of fake emails claiming to be from the IRS. Don't buy it.