Opinion

HTML e-mail & why it’s not a good idea

Many people today send and receive e-mails in HTML format. It’s nice to look at, you can format it easily, you can add pictures and more. In fact, when you read an HTML e-mail, you’re effectively reading a web page … and therein lies the problem!

There’s no shortage of vulnerabilities in IE, many of which have been exploited by viruses, worms and Trojans over the last few years. And the ‘lead-time’ between the discovery of a vulnerability and the appearance of an exploit that targets it has become progressively shorter.

So HTML is intrinsically insecure. Even if an HTML e-mail looks like regular text, it may be more than that. It’s possible to embed script within it that will execute automatically [including exploit instructions]. This may harm your machine directly or leave it open to attack.

Recent reports suggest that ‘phishers’ have started to make use of HTML e-mails. In a ‘classic’ phishing scam, the user receives an e-mail that is made to look like it has come from their bank. There’s a link to a web site that’s designed to look like their bank’s web site. The user is prompted to input their personal details, which are then captured by the phisher. Of course, in order to succeed, the scam requires an unsuspecting user to click on the link and enter their details.

Now, however, it seems that phishers are trying to ‘cut out the middleman’ and launch the fraudulent web site automatically. This is done by sending an HTML e-mail containing hidden script instructions designed to edit the user’s hosts file. So when they next try to access their bank, they are re-directed to the fraudulent web site.

One more reason to use plain text e-mail, rather than HTML, and to disable scripting on your machine.

HTML e-mail & why it’s not a good idea

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Reports

Ferocious Kitten: 6 years of covert surveillance in Iran

Ferocious Kitten is an APT group that has been targeting Persian-speaking individuals in Iran. Some of the TTPs used by this threat actor are reminiscent of other groups, such as Domestic Kitten and Rampant Kitten. In this report we aim to provide more details on these findings.

Andariel evolves to target South Korea with ransomware

In April 2021, we observed a suspicious Word document with a Korean file name and decoy. It revealed a novel infection scheme and an unfamiliar payload. After a deep analysis, we came to a conclusion: the Andariel group was behind these attacks.

Operation TunnelSnake

A newly discovered rootkit that we dub ‘Moriya’ is used by an unknown actor to deploy passive backdoors on public facing servers, facilitating the creation of a covert C&C communication channel through which they can be silently controlled. The victims are located in Africa, South and South-East Asia.

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