RTF malware analysis — malicious · d45223b23daf34e3

MALICIOUS

RTF

2.72 MB First seen: 2023-08-08

MD5: 2ddb70c824caef7db50b7c30968871e2 SHA-1: a7395f10d5e67f005791c578169aaefb5282c1b1 SHA-256: d45223b23daf34e347b0056f52135e14b61e8fd5ee2bfdc1d1ef48693cf19d49

280 Risk Score

Malware Insights

MITRE ATT&CK

T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF file contains multiple indicators of exploitation for CVE-2017-11882, including OLE objects and specific Equation Editor ProgIDs. The presence of a PE header within the hex-encoded OLE object data strongly suggests that the exploit is used to drop and execute a secondary payload. No specific family could be identified, but the exploit vector is clear.

Heuristics 7

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
\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 ~1809KB 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off000800a1.bin` `7650d858c44080dc58ac8fe8e5b298b66dcebf8530fd3374dd1f90b6f7708dd8`	rtf-objdata-decoded	RTF \objdata at offset 0x800A1	657377 bytes
`objdata_01_off001cc0b6.bin` `204b2540f8ab269f1b685c8febf282aa6c207b9ad5643aeb82ab0420e9cf6b68`	rtf-objdata-decoded	RTF \objdata at offset 0x1CC0B6	198315 bytes

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