7-Zip Archive (.7z) Malicious Email Attachments

7-Zip Archive (.7z) Malicious Email Attachments

Online users who have received unexpected email messages with attached files with names ending with ".7z" are asked not to open them. This is because the fake email messages are being sent by cyber criminals and the attachments are 7-Zip compressed archived files that contain malware, malicious programs or computer viruses. And, any attempt to open the malicious attachments will result in the recipients getting their computers infected with a virus, Trojan horse, spyware, ransomware or other malware.

A Sample of a Malicious 7-Zip Archive (.7z) Email Message

Subject: Emailed Invoice - 107681:1

Date: Wed 30/08/2017 22:04

From: Nickolas Leonard

Attachment: I_107681-1.7z (3 KB)

As requested



Nickolas Leonard

The 7-Zip compression is similar to ZIP which is the most popular file compression or archive formats.

Cyber criminals usually store their malware in compressed files to help prevent antivirus software from detecting them. In other words, they do it because the compressed malicious email attachments may bypass the recipients' antivirus software.

What is a 7-Zip file?

Files with the extension .7z are compressed archive files created with 7-Zip open source software. These files are created using a compression method called LZMA, which is an algorithm for lossless data compression—a type of compression known for reducing file size while preserving quality.

Check the comment section below for additional information, share what you know, or ask a question about this article by leaving a comment below. And, to quickly find answers to your questions, use our search Search engine.

Note: Some of the information in samples on this website may have been impersonated or spoofed.
Was this article helpful?  +
Share this with others:

Comments, Questions, Answers, or Reviews

Comments (Total: 9)

To protect your privacy, please remove sensitive or identifiable information from your comments, questions, or reviews. We will use your IP address to display your approximate location to other users when you make a post. That location is not enough to find you.

Your post will be set as anonymous because you are not signed in. An anonymous post cannot be edited or deleted, therefore, review it carefully before posting. Sign-in.

The comments, reviews or answers below do not necessarily reflect the views of Online Threat Alerts (OTA).

  • February 12, 2020 at 7:05 AM by info

    "Notice to appear in Court


    Wed 2/12/2020 7:48 AM

    From: Angela Marone - angelamarone@icj.com

    Document_Court_Order.7z (15 KB)

    - Notice to appear in Court #0368759073 -

    You are requested to appear in court on Friday the 14th of Febraury 2020 at 10:00 AM.

    Please, do not forget to bring all the documents related to this case. Herein attached are the Court Order and other documents pertaining to this case; including the court address and contact information.

    FILE ID is: CASE#0368759073

    Note: The case will be heard by the judge in your absence (if you do not attend) and the Court may issue an arrest warrant for your arrest. If a warrant is issued for your arrest, you may be held in custody until your brought before the Court .

    Yours faithfully,

    Angela Malone.

    Clerk of Court."

    Another malicious email.

  • December 27, 2017 at 11:10 PM by an anonymous user from: Quezon City, National Capital Region, Philippines

    Hi! Just received one attachment via facebook messenger with a file as video_8095.mp4.7z as an attachment. The messenger app cannot view it but is seen from the browser. Is this also the same malware infected program? I am hesitant to open it.

    • December 28, 2017 at 9:43 PM by an anonymous user from: San Juan, National Capital Region, Philippines

      Got also one today. Did't open it.

    • December 28, 2017 at 12:11 PM by an anonymous user from: Tacloban City, Eastern Visayas, Philippines

      dont open it! mobile phone messenger cant open it since its not intended to ran on mobile phones, and just what the article said it will infect your pc.. so it is intended to harm your computer..

  • December 26, 2017 at 12:05 PM by an anonymous user from: Lecanto, Florida, United States


    Received similar .7z attachment email

    Sender (Terrell@mail316.us3.mcdlv.net)

    Attachment: CCE26122017_006144.7Z

    Attachment naming scheme seems to be letters (CCE) followed by today's date (26122017) = 26-12-2017.

  • December 20, 2017 at 9:32 PM by info

    Here is another scam:

    "Voicemail from 01770405763 <01770405763> 2m 22s

    Message From "01770405763" 01770405763

    Created: Thu, 21 Dec 2017 07:54:00 0700

    Duration: 2m 22s

    Attachment: msg_21_12_01770405763-8442763.7z 2 KB"

  • September 29, 2017 at 11:34 AM by info

    Here is another scam:


    Fri 29/09/2017 11:30

    From: "Roberto Kilner"

    Attachment: 869572.7z


    Invoice attached for the Office365 account.


    Roberto Kilner"

  • September 27, 2017 at 1:38 AM by info

    Here is another scam:

    "Subject: Invoice PIS3021721

    Date: Tue 26/09/2017 23:25

    From: AutoPosted PI Notifier

    Attachment: InvoicePIS3021721.7z

    Please find Invoice PIS3021721 attached."

  • September 3, 2017 at 8:15 PM by info

    Received the following question via a Facebook message:

    "Is the app 7 Zip itself malware?"


    No, 7-Zip is not a malware. It is a legitimate and free file compression format used to reduce the size of files.

    But, cyber criminals are using it to store their malware in, to help prevent antivirus software from detecting them.

Comments Show More Comments (8)

Write Your Comment, Question, Answer, or Review

7-Zip Archive (.7z) Malicious Email Attachments