Malicious RTF — malware analysis report

Static analysis result for SHA-256 3c32fb1682bcd492…

MALICIOUS

RTF

48.0 KB First seen: 2025-10-01
MD5: 9ae3dffc1ec1bdc0d877bafd58ee1650 SHA-1: 14f0dfaccf77ffd32a37a03877a29bc6310e9f69 SHA-256: 3c32fb1682bcd492021f7d18178c31f795020f80a5e5477edbe8117d8b768229
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an RTF document that contains an embedded OLE object, specifically targeting the Equation Editor vulnerability. The \objupdate directive indicates that the OLE object is automatically activated upon opening the document, leading to the exploitation of the Equation Editor. This technique is commonly used to download and execute a secondary payload, hence the high confidence in the attack pattern.

Heuristics 3

  • 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 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001971.bin
bd5bc4819857eb381c43a81476e09e9a8c00a3f692599e95cafb9ca34838c333
rtf-objdata-decoded RTF \objdata at offset 0x1971 1595 bytes