Class: Hoax
A hoax is a fake warning about a virus or other piece of malicious code. Typically a hoax takes the form of an e-mail message warning the reader of a dangerous new virus and suggesting that the reader pass the message on. Hoaxes cause no damage in themselves, but their distribution by well-meaning users often causes fear and uncertainty. Most anti-virus vendors include hoax information on their web sites and it is always advisable to check before forwarding warning messages.Read more
Platform: Win32
Win32 is an API on Windows NT-based operating systems (Windows XP, Windows 7, etc.) that supports execution of 32-bit applications. One of the most widespread programming platforms in the world.Family: Hoax.Win32.ArchSMS
No family descriptionExamples
9032FBD08CB1BA9ED6606047AA3C06E61827466CBE2A3BF25A66E1E815B92167
C05190F5E81BA0DD46B9A020E4195161
E7838D767EC9E27436DBF28CC1382C3C
579F9F60760E758DEF580E5F98F3CBDB
Tactics and Techniques: Mitre*
Adversaries may abuse a double extension in the filename as a means of masquerading the true file type. A file name may include a secondary file type extension that may cause only the first extension to be displayed (ex: File.txt.exe may render in some views as just File.txt). However, the second extension is the true file type that determines how the file is opened and executed. The real file extension may be hidden by the operating system in the file browser (ex: explorer.exe), as well as in any software configured using or similar to the system’s policies.(Citation: PCMag DoubleExtension)(Citation: SOCPrime DoubleExtension)
Adversaries may abuse double extensions to attempt to conceal dangerous file types of payloads. A very common usage involves tricking a user into opening what they think is a benign file type but is actually executable code. Such files often pose as email attachments and allow an adversary to gain Initial Access into a user’s system via Spearphishing Attachment then User Execution. For example, an executable file attachment named Evil.txt.exe may display as Evil.txt to a user. The user may then view it as a benign text file and open it, inadvertently executing the hidden malware.(Citation: SOCPrime DoubleExtension)
Common file types, such as text files (.txt, .doc, etc.) and image files (.jpg, .gif, etc.) are typically used as the first extension to appear benign. Executable extensions commonly regarded as dangerous, such as .exe, .lnk, .hta, and .scr, often appear as the second extension and true file type.
Adversaries may abuse a double extension in the filename as a means of masquerading the true file type. A file name may include a secondary file type extension that may cause only the first extension to be displayed (ex: File.txt.exe may render in some views as just File.txt). However, the second extension is the true file type that determines how the file is opened and executed. The real file extension may be hidden by the operating system in the file browser (ex: explorer.exe), as well as in any software configured using or similar to the system’s policies.(Citation: PCMag DoubleExtension)(Citation: SOCPrime DoubleExtension)
Adversaries may abuse double extensions to attempt to conceal dangerous file types of payloads. A very common usage involves tricking a user into opening what they think is a benign file type but is actually executable code. Such files often pose as email attachments and allow an adversary to gain Initial Access into a user’s system via Spearphishing Attachment then User Execution. For example, an executable file attachment named Evil.txt.exe may display as Evil.txt to a user. The user may then view it as a benign text file and open it, inadvertently executing the hidden malware.(Citation: SOCPrime DoubleExtension)
Common file types, such as text files (.txt, .doc, etc.) and image files (.jpg, .gif, etc.) are typically used as the first extension to appear benign. Executable extensions commonly regarded as dangerous, such as .exe, .lnk, .hta, and .scr, often appear as the second extension and true file type.
* © 2024 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.