Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 65f8af30e604928d…

MALICIOUS

RTF / .DOC

74.0 KB
MD5: 24eba911a46b8a6ccd1c236343ad0dd7 SHA-1: 886359cfe688847daa987cf67e863b27e6248715 SHA-256: 65f8af30e604928dbd699a602303550b7cc3649029ee219bf635309e42ed71a7
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document containing OLE object data and specifically triggers heuristics for the Equation Editor vulnerability. The ".objupdate" directive indicates that the embedded OLE object is automatically activated upon opening, leading to exploitation. This is a common method for delivering second-stage malware.

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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00002056.bin
9c8351540e75ef276ebfaffb46221072e92caf145237394364f157e5e311d1cc
rtf-objdata-decoded RTF \objdata at offset 0x2056 1750 bytes