The tidal wave of Chinese hack attacks on the U.S. in recent weeks, from The New York Times and the Defense Department to Facebook and now even Apple, have one increasingly common and sophisticated type of malware trick in common: "spear-phishing." The tech giants seem to be the victim of a site called iPhonedevSdk, while WikiLeaks and a new cyber-espionage report appear to connect hacked Cabinet-level emails with a Chinese army-linked group known as "Comment Crew." But beyond the initial paranoia that we may be on the brink of "an asymmetrical digital with China," you'd be forgiven for asking: If tech giants and the government can fall prey to a bad link in an email, why can't I? As some have quipped, targeted spear-phishing emails are "not a terribly sophisticated attack" — it's advance spam, really — but just because the more complex spear-phishing schemes make up a fraction of basic phishing scams doesn't mean you and your company can't avoid embarrassment. Spear-fishing does pay off for hackers 40-to-1, after all. This new round of attacks may be more sophisticated than that, as Facebook has insisted since it unveiled its internal vulnerability on Friday, but here's a starter guide on how not to be that guy, just in case the Chinese hacker war hits your inbox next:

Step 1: Understand the Difference Between Phishing and Spear-Phishing

Phishing attacks are the more blatantly malicious ones — they come from big organizations sending generic emails from generic addresses to thousands of inboxes, hoping that just some of the malware recipients will click a malicious link or download an infected file. A common phishing scam is a fake version of your bank asking you for your online banking login, but it gets worse than that

Spear-phishing, on the other hand, targets a small group of specific users, as ComputerWorld's Gregg Keizer explained in a 2011 post. And instead of coming from a big company or social-media network, these emails come from senders who appear to be colleagues or friends. They also tend to include personalized touches, as security firm Norton explains on its site:

The salutation on the email message is likely to be personalized: "Hi Bob" instead of "Dear Sir." The email may make reference to a "mutual friend." Or to a recent online purchase you've made. Because the email seems to come from someone you know, you may be less vigilant and give them the information they ask for.

Step 2: Check the Sender's Full Email Address  

Often spear-phishing emails will look like they come from a trusted friend or colleague, but the name isn't always the thing when it comes to email. In its report linking the Chinese hacking group known as "Comment Crew" to the Chinese People's Liberation Army, the cyber-security firm Mandiant used this example:

 

Kevin Mandia is Mandiant's CEO, which, despite the dubious "details click here" line, makes this seem like a totally real email — Mandiant is good at PR, if its coordination with its former clients and soon-to-be partners at The New York Times on the China report's reveal is any example. However, upon closer inspection, that domain — kevin.mandia@rocketmail.com — probably doesn't belong to Mandia. Would the CEO of a major technology watchdog really use Rocketmail?

Step 3: Remember That Hackers Can Email Back, Too

So one obvious way to test a shady email from a shady person would be ... to respond. Turns out, that's not a foolproof tactic for checking the viability of a sensitive message. The Mandiant cybersleuths actually wrote back to one of the Chinese hackers they were in the process of outing: "I'm not sure if this is legit, so I didn't open it." Within 20 minutes, someone responded back: "It's legit." Just because it sounds like your friend doesn't ever mean that it is. A better way to double-check would be to contact the "friend" in a separate email, via phone, or by any other means. 

Step 4: Check the Attachment File Type Closely

Most spear-phishing files come in .zip format, according to the Mandiant report. But, often these hackers dress up Zip files as PDFs in disguise, like this:

While that looks like a standard .pdf file, Adobe icon and all, that little elipses is revealing. The file name continues after the PDF extension to include 119 spaces folowed by .exe, according to the Mandiant report. 

Step 5: Check for Vague Filenames

While spear-phishing emails have an incredible amount of personalization, the files go for a more generic string of words. Something like "updated_office_contact_v1.zip" is common. The file names also tend to include military, economic, and diplomatic themes, largely because of the types of organizations these hackers attack. 

Step 6: Be Paranoid

This one comes from security researchers at Georgia Tech: "It's very difficult to put technical controls into place to prevent humans from making a mistake. To keep these attacks out, email users have to do the right thing every single time," writes malware expert Andrew Howard. "Users are the front line defense. We need every user to have a little paranoia about email." 

Image via Shutterstock by Ivelin Radkov