SpiderLabs Blog

Insta-Phish-A-Gram | Trustwave

Written by Homer Pacag | Oct 27, 2022 5:00:00 AM

Following Trustwave SpiderLabs’ blog on social media-themed phishing on Facebook, comes another flavor of ‘infringement’ phishing. In this case, the targets, still under the umbrella of Meta, are Instagram users. This theme is not new, and we have seen it from time to time over the last year. It’s the same copyright infringement trickery again, but this time, the attackers gain more personal information from their victims and use evasion techniques to hide phishing URLs.

Anyone can file a copyright report with Instagram if the account owner finds that their photos and videos are being used by other Instagram users. The Copyright Report form can be filed at this link. This report form is the locus of ‘copyright infringement appeals’ phishing attacks, which seek to trick its victims into giving away their user credentials and personal information.

Figure 1. Instagram’s Form to file Copyright Infringement

The example below shows the email sample we analyzed. Notice that the from address looks made-up and purports to be from ‘metahelpcenter.org’, which is a non-existent address and a domain name for sale.

Figure 2. The raw phishing email shows that the victim is infringing copyright.

We analyzed the email in a text editor, found the ‘Appeal Form’ button, and the location to which it links. The URL employs an evasive technique - using a URL rewrite or redirector, hxxps://l[.]wl[.]co/l?u=, followed by the true phishing URL, hxxps://helperlivesback[.]ml/5372823, in the query part of the URL.  The WL[.]CO domain is owned by WhatsApp. This is an increasingly common phishing trick, using legitimate domains to redirect to other URLs in this fashion.

Figure 3. More examples of redirectors used in phishing

Clicking the ‘Appeal Form’ button opens the default browser and redirects the user to the intended phishing webpage. As the victim enters their username, the data is sent to the server via the form ‘POST’ parameters. In our case, we used “dummyusername”. We monitored data being sent to the server, as shown in the following consecutive steps.

Figure 4. Notice the page says copyright, right? They can’t even spell it right.

After clicking the Continue button, the typed username is displayed, now prefixed with the @ symbol. The page asked for the password, and we typed in “dummypassword”. As the victim clicks the continue button, the entered data also continues to be sent to the server.

Figure 5. And then your password...

The form is not satisfied the first time the user types in their password. Then, the form asks the user to type in the password once more. There’s also another question field to fill in, which asks which city you live in. We typed in “everywhere”. Once again, the data is sent back to the server via ‘POST’.

Figure 6. Sometimes, I wonder what’s it for the phishers to know where you are.

In the last step, the form asks for the user’s telephone number. We input descending numbers 9 to 1 as a dummy telephone number. This telephone number data can potentially be used for Two-Factor Authentication(2FA). Also, it could be sold on the dark web, perhaps leading to future scam telephone calls.

Figure 7. Almost done what? Stealing?

At this stage, the personal information has been harvested and the victim is then redirected to the final page which is Instagram’s actual help page. The user is now back to the beginning of the copyright reporting process, as mentioned in the beginning of the blog.

Figure 8. Instagram’s real help page

In conclusion, we are seeing URL redirection more and more in phishing attacks. For this spam phishing campaign, malware creators leveraged URL redirection with a WhatsApp domain to steal personal information from victims using messages crafted to appear urgent. It can be difficult for most URL detection systems to identify this deceptive practice, as the intended phishing URLs are embedded mostly in the URL query parameters.

Trustwave MailMarshal defends against this type of phishing campaign. 

IOCs:

URL

hxxp://helperlivesbacks[.]ml/5372823

hxxp://helperlivesbacks[.]ml/5372823/status

hxxp://helperlivesbacks[.]ml/5372823/statusx

hxxp://helperlivesbacks[.]ml/5372823/statusf