No Message Callers & Twitter Spam

Cybersecurity risks associated with phone calls and a side note on Twitter spam

One of my posts on Cybersecurity.

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Deluge of calls that leave no messages

I don’t know about you but I’m really tired of getting calls with no messages. This activity has picked up dramatically recently. I never answer the phone unless I recognize the number or I am expecting a call. If people want to call me, they need to schedule it through IANS Research or they are an existing friend, client, or vendor already in my contact list. Usually those people will leave a message.

As I mention many times on my website and elsewhere, the best way to reach me if you want to hire me is through LinkedIn. (Please read my profile before contacting me.) Using LinkedIn is one way I can see who is contacting me and try to verify them before doing business with a person — especially if they are going to have me attack their website in a penetration test or scan their cloud systems in a cloud security assessment. I have no way to verify a person on a random phone call.

If all these phone calls really are just marketing robocalls, they sure do hound people. They also pay no attention to the voicemail greeting that says, “If you don’t leave a number you will be blocked, so please do leave a message.” I have resorted to adding every number that calls and does not leave a number to a contact that I block. I figure if it is important enough, the person will figure out how to reach me another way.

What could an attacker do with a random phone call?

Some known attacks exist like Vishing — where a call gets you on the phone and tries to trick you into doing something. In some cases, phone calls have used impersonation to get a caller to send money to to the wrong bank account. Sometimes they will try to trick you into giving out account information. Sometimes they just try to get you to say “Yes” so they can record you doing that and use it elsewhere.

Beyond that, do you search for and click on web pages to try to figure out who called? A crafty attacker might randomly call people to get them to click on a web page with malware in it. I’ve never heard of such a thing, but I started thinking about the possibly due to the sheer number of calls I’ve been getting lately. I often look up the number in Google but I don’t click on the websites. I just peruse the list to see if there’s any useful information in the Google search results.

How else might getting you to click on a link to look up a number benefit an adversary? Perhaps they can call, you look up the number, and they can associate your phone number with an IP address if you look up the number right after they call. That could be useful if they are trying to figure out the IP address of high wealth individuals or someone they know owns bitcoins, for example. Here’s how that would work:

• Attacker calls from random number.
• Target individual looks up number on various web pages right after the call.
• Attacker has the target’s IP address in the web logs.
• Even better if they leave a description of the call so the attacker can verify they got the right target.
• Now the attacker knows what IP address to go after to try to steal your bitcoins or whatever.

Alternatively…I could just be getting loads and loads of spammy robocalls that want to poll me on who I am going to vote for or try to sell me some kind of service. The calls could even be generated by the robocall blocking companies that get you to their website and then try to coerce you into signing up for their blocking service. I don’t know. But it’s really getting out of hand.

Here are some of the numbers that called me recently and did not leave a message. Some could be spoofed, meaning the call looks like it is coming from a certain number but it’s not really.

+1 (206) 909–4034‬

+1 (206) 673–2781‬

‭+1 (206) 681–9279

‭+1 (206) 336–3464‬

+1 (206) 603–2257‬

+1 (206) 413–3801‬

+1 (206) 207–5629‬

+1 (360) 799–8249‬

+1 (206) 888–9722‬

+1 (509) 450–1035‬

+1 (425) 650–1250‬

+1 (206) 900–0310‬

+1 (262) 229–8770‬

+1 (206) 900–0126‬

+1 (770) 250–2060‬

+1 (206) 487–3429‬

+1 (281) 766–5540‬

+1 (206) 207–5628‬

‭+1 (478) 221–8011‬

+1 (307) 200–0811‬

+1 (385) 465–6943‬

+1 (509) 566–0198‬

+1 (918) 625–9721‬

+1 (206) 535–1148‬

+1 (206) 973–3385‬

‭+1 (414) 877–3011‬

+1 (206) 401–3406‬

I don’t think any of these are legitimate, but if for some reason you recognize one of these numbers and can identify it feel free to DM me on Twitter. Please include in your initial message: 1.) the phone number and 2.) who owns it.

Twitter Spam

Since I’m asking you to DM me if you have information about these numbers, I should also explain how I use Twitter messaging. Sometimes it takes me a while to get to Twitter DMs and often I don’t respond, because I don’t know if they are legitimate requests or not. So if I don’t respond to your message please don’t be insulted. I work in cybersecurity and I’m risk averse!

In the past security researchers have been tricked by people who want to “collaborate.” I never respond to Twitter messages that start with “hi” and no indication of what the person wants. I get that a lot. People also keep trying to get me to post their articles. I don’t post random articles sent to me from unknown sources.

I also don’t participate in those tweet chat sessions. I did that once and turned out that most of the accounts commenting in the tweet chat looked fake upon further inspection. It seems to be some sort of marketing tactic I don’t understand — or care to — so please don’t explain it to me. It’s not my thing.

I also don’t want to be an “influencer” as I explain in my LinkedIn profile. I’m just trying to help people with cybersecurity so I post information people may find useful. I cannot remain honest and unbiased if people pay me to post their content, so I don’t do that.

And by the way I don’t really get #FollowFriday. I really appreciate the acknowledgement, but it rarely gets me new followers and ends up creating a lot of noise in my feed. It’s super nice to be appreciated, but perhaps just recommend to someone in person that they could follow me here on Medium (which provides me some income for my time), or recommending my book and provide a link to that instead? I don’t know. Maybe I’m just not hip enough to understand it, but #FollowFriday doesn’t seem to really work as far as I can tell.

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Teri Radichel | © 2nd Sight Lab 2021

About Teri Radichel:
~~~~~~~~~~~~~~~~~~~~
⭐️ Author: Cybersecurity Books
⭐️ Presentations: Presentations by Teri Radichel
⭐️ Recognition: SANS Award, AWS Security Hero, IANS Faculty
⭐️ Certifications: SANS ~ GSE 240
⭐️ Education: BA Business, Master of Software Engineering, Master of Infosec
⭐️ Company: Penetration Tests, Assessments, Phone Consulting ~ 2nd Sight Lab

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