Re: Invoice coming from random senders and random email addresses with a semi random zip attachment the zip is always called invoice(random number).zip is another one from the current bot runs which try to download various Trojans and password stealers especially banking credential stealers, which may include cridex, dridex, dyreza and various Zbots, cryptolocker, ransomware and loads of other malware on your computer. They are using email addresses and subjects that will entice a user to read the email and open the attachment. A very high proportion are being targeted at small and medium size businesses, with the hope of getting a better response than they do from consumers.
We are also seeing loads of other emails today pretending to come from RBC Express <ISVAdmin@rbc.com> and HMRC.gov.uk <email@example.com> with a subject of invoices, along with a Lloyds Bank – Pendeford Securities – Please Read Action Required/PI Documents/ Region code East 2/ 4084583/ These 3 have a different malware payload ( VirusTotal)
Almost all of these also have a password stealing component, with the aim of stealing your bank, PayPal or other financial details along with your email or FTP ( web space) log in credentials. Many of them are also designed to specifically steal your Facebook and other social network log in details.
All the alleged senders, companies, names of employees and phone numbers mentioned in the emails are all innocent and are just picked at random. Some of these companies will exist and some won’t. Don’t try to respond by phone or email, all you will do is end up with an innocent person or company who have had their details spoofed and picked at random from a long list that the bad guys have previously found. The bad guys choose companies, Government departments and organisations with subjects that are designed to entice you or alarm you into blindly opening the attachment or clicking the link in the email to see what is happening.
Please read our How to protect yourselves page for simple, sensible advice on how to avoid being infected by this sort of socially engineered malware.
The email looks like:
Check Invoice number
9 june 2015: Invoice (42).zip: Extracts to: Invoice_store.exe Current Virus total detections :2/57
This is another one of the spoofed icon files that unless you have “show known file extensions enabled“, will look like a proper PDF file instead of the .exe file it really is, so making it much more likely for you to accidentally open it and be infected.
Be very careful with email attachments. All of these emails use Social engineering tricks to persuade you to open the attachments that come with the email. Whether it is a message saying “look at this picture of me I took last night” and it appears to come from a friend or is more targeted at somebody who regularly is likely to receive PDF attachments or Word .doc attachments or any other common file that you use every day.
The basic rule is NEVER open any attachment to an email, unless you are expecting it. Now that is very easy to say but quite hard to put into practice, because we all get emails with files attached to them. Our friends and family love to send us pictures of them doing silly things, or even cute pictures of the children or pets.
Never just blindly click on the file in your email program. Always save the file to your downloads folder, so you can check it first. Most ( if not all) malicious files that are attached to emails will have a faked extension. That is the 3 letters at the end of the file name. Unfortunately windows by default hides the file extensions so you need to Set your folder options to “show known file types. Then when you unzip the zip file that is supposed to contain the pictures of “Sally’s dog catching a ball” or a report in word document format that work has supposedly sent you to finish working on at the weekend, you can easily see if it is a picture or document & not a malicious program. If you see .EXE or .COM or .PIF or .SCR at the end of the file name DO NOT click on it or try to open it, it will infect you.
While the malicious program is inside the zip file, it cannot harm you or automatically run. When it is just sitting unzipped in your downloads folder it won’t infect you, provided you don’t click it to run it. Just delete the zip and any extracted file and everything will be OK. You can always run a scan with your antivirus to be sure. There are some zip files that can be configured by the bad guys to automatically run the malware file when you double click the zip to extract the file. If you right click any suspicious zip file received, and select extract here or extract to folder ( after saving the zip to a folder on the computer) that risk is virtually eliminated. Never attempt to open a zip directly from your email, that is guaranteed way to get infected. The best way is to just delete the unexpected zip and not risk any infection.