How a Malicious Excel File (CVE-2017-0199) Delivers the FormBook Payload

    Date: 06/06/2025

    Severity: High

    Summary

    Our team recently identified a high-severity phishing campaign targeting users of outdated Microsoft Office applications through malicious email attachments. The emails contain an Excel file that exploits the CVE-2017-0199 vulnerability in the OLE (Object Linking and Embedding) feature of older Office versions. The campaign distributes FormBook, an infostealer malware capable of capturing login credentials, keystrokes, and clipboard data. Once the malicious file is opened, a sequence of actions is triggered to deploy the FormBook payload.

    Indicators of Compromise (IOC) List

    Domains\URLs: 

    http://172.245.123.32/xampp/hh/wef.hta

    http://172.245.123.32/199/sihost.exe

    Hash : 

    33A1696D69874AD86501F739A0186F0E4C0301B5A45D73DA903F91539C0DB427

    2BFBF6792CA46219259424EFBBBEE09DDBE6AE8FD9426C50AA0326A530AC5B14

    7E16ED31277C31C0370B391A1FC73F77D7F0CD13CC3BAB0EAA9E2F303B6019AF

    A619B1057BCCB69C4D00366F62EBD6E969935CCA65FA40FDBFE1B95E36BA605D

    3843F96588773E2E463A4DA492C875B3241A4842D0C087A19C948E2BE0898364

    Gurucul Threat Detection and Incident Response (TDIR) Queries for Detection

    Domains\URLs: 

    domainname like "http://172.245.123.32/xampp/hh/wef.hta" or url like "http://172.245.123.32/xampp/hh/wef.hta" or siteurl like "http://172.245.123.32/xampp/hh/wef.hta" or domainname like "http://172.245.123.32/199/sihost.exe" or url like "http://172.245.123.32/199/sihost.exe" or siteurl like "http://172.245.123.32/199/sihost.exe"

    Hash : 

    sha256hash IN ("2BFBF6792CA46219259424EFBBBEE09DDBE6AE8FD9426C50AA0326A530AC5B14","33A1696D69874AD86501F739A0186F0E4C0301B5A45D73DA903F91539C0DB427","A619B1057BCCB69C4D00366F62EBD6E969935CCA65FA40FDBFE1B95E36BA605D","7E16ED31277C31C0370B391A1FC73F77D7F0CD13CC3BAB0EAA9E2F303B6019AF","3843F96588773E2E463A4DA492C875B3241A4842D0C087A19C948E2BE0898364")

    Reference:

    https://www.fortinet.com/blog/threat-research/how-a-malicious-excel-file-cve-2017-0199-delivers-the-formbook-payload


    Tags

    MalwareCVE-2017VulnerabilityFormBookExploitInfostealer

    « Previous Article

    Comments

    No records to display

    Looking for Something?
    Threat Research Categories:
    Tags