RTF / .DOC malware analysis — malicious · 494cf04c6406ba86

MALICIOUS

RTF / .DOC

3.77 MB First seen: 2022-05-24

MD5: 58e1d6f601041b7bafc0f3b0a0bd3beb SHA-1: 882e839bfcf62cceae76a0bd42e60bf5f9a45870 SHA-256: 494cf04c6406ba864ce890869984fa9e779751b0ad76c0e55ab28ec898d088b9

342 Risk Score

Malware Insights

MITRE ATT&CK

T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains multiple indicators of exploitation for CVE-2017-11882, including OLE object data, Equation Editor activation, and a PE header within hex data. These heuristics strongly suggest the document is designed to drop and execute a secondary payload, as indicated by ClamAV's detection of Rtf.Dropper.Agent-9965975-1. The embedded artifacts, objdata_00_off00001291.bin and objdata_01_off001e9d65.bin, are likely the dropped payload.

Heuristics 9

Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED

RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR

RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
PE header (with DOS stub) in hex data critical RTF_MZ_HEX

Hex-encoded PE (MZ + DOS stub) found inside RTF — likely an embedded executable payload
ClamAV: Rtf.Dropper.Agent-9965975-1 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Rtf.Dropper.Agent-9965975-1
\objupdate forces OLE activation high RTF_OBJUPDATE

RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX

RTF contains ~1857KB of hex-encoded data inside \objdata sections — may hide a payload
OLE object data medium RTF_OBJDATA

RTF contains 2 \objdata section(s) — embedded OLE objects
Embedded OLE object medium RTF_OBJEMB

RTF contains \objemb — embedded OLE object
Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE

One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off00001291.bin` `7d9fef2bdec5f1b7bebe5ad0eccf524928fe2bb24903ad5265cd1fa66a8edb09`	rtf-objdata-decoded	RTF \objdata at offset 0x1291	960300 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 7.85, consistent with packed or encrypted content.
`objdata_01_off001e9d65.bin` `b5fb24d310a9bf9f48aea8e381ad105e2f4a64fcacf54516332e6d3acbd8cb23`	rtf-objdata-decoded	RTF \objdata at offset 0x1E9D65	462306 bytes

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