RTF / .DOC malware analysis — malicious · 93a20a7e0a91818b

MALICIOUS

RTF / .DOC

2.13 MB First seen: 2022-03-14

MD5: fa7fe1ae74c0d42d133afc0466a751f5 SHA-1: 063a172dd8fd0c68a69ade76b29137960f07f337 SHA-256: 93a20a7e0a91818bae1264484c16c5c94a146397657a9c4019e18b6a5a13b08b

180 Risk Score

Malware Insights

MITRE ATT&CK

T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The critical RTF_EQUATION_EDITOR heuristic and high CVE_2017_11882_ACTIVATION_RELATED heuristic indicate the file is designed to exploit the Equation Editor vulnerability. The RTF_OBJUPDATE heuristic further suggests that the embedded OLE object is intended to be activated, likely leading to arbitrary code execution. The presence of OLE object data and the specific Equation Editor class name strongly support this attack vector. No scripts were extracted, and the document body was truncated, limiting further analysis of the payload.

Heuristics 5

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.
\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.
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

Extracted artifacts 2

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off000012c5.bin` `d16ab0e119c0f9ef7cc735e9e1f44022d9ae8e1932806419dd909b26b7df140d`	rtf-objdata-decoded	RTF \objdata at offset 0x12C5	98402 bytes
`objdata_01_off00045039.bin` `f9fb1ae16ce2ffc51b4e5451657ab58729816beafa0f4ff3f9445093401acb66`	rtf-objdata-decoded	RTF \objdata at offset 0x45039	462938 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.