This Trojan arrives as attachment to email messages spammed by another malware or a malicious user.

Upon execution, it exploits the Macro Validation Vulnerability in Microsoft Excel wherein a specially crafted document can cause the application to drop and execute an embedded .EXE file.
More information about the said vulnerability can be found here.
Once it successfully exploits the mentioned vulnerability, it is able to execute a shell code which, in turn, runs the embedded .EXE file on the affected system. The said file is detected by Trend Micro as BKDR_ACCDROP.F. It may be downloaded unknowingly by a user when visiting malicious Web site(s).


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