ISS or Internet Information Services is merely a name for Microsoft's web server.

Explanation:
Internet Information Services (IIS, 2S) is an extensible web server created by Microsoft for use with the Windows NT family.[2] IIS supports HTTP, HTTP/2, HTTPS, FTP, FTPS, SMTP and NNTP. It has been an integral part of the Windows NT family since Windows NT 4.0, though it may be absent from some editions (e.g. Windows XP Home edition), and is not active by default
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A backdoor is basically just a ثغرة

Explanation:

“A backdoor refers to any method by which authorized and unauthorized users are able to get around normal security measures and gain high-level user access (aka root access) on a computer system, network, or software application.”
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And of course the self-explanatory part:

Module -> وحدة which refers to a block of code

Malicious -> خبيثة to insinuate that it is not a friendly/consensual block of code entering our system.

English term (edited): malicious IIS backdoor module

يشيع في المجال التقني استخدام "الباب الخلفي" كما في هذه المصادر:
https://forum.arabhardware.net/showthread.php?t=71498
https://seomastar.com/backdoor-security/
https://technologyreview.ae/technodad/هجوم-الباب-الخلفي/

انظر ما جاء في مصطلحات ميكروسوفت:





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Note added at 23 hrs (2023-10-27 14:32:02 GMT)
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In this context, a "malicious IIS backdoor" refers to a harmful software module or component that has been specifically designed to compromise and exploit Internet Information Services (IIS), which is a web server software developed by Microsoft. The term "backdoor" indicates that this module allows unauthorized and potentially malicious access to a system or network, often without detection, enabling attackers to carry out various malicious activities. The use of the term "malicious" underscores the intent of this module to cause harm or engage in unauthorized actions.