Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 de298d9917d07fdf…

MALICIOUS

RTF / .DOC

4.6 KB First seen: 2022-03-30
MD5: 8d5e1170a5ba784c59cec6927772c44c SHA-1: 80cf1dfd29cb0b7de35e93bec97cfb13fcc1c4a5 SHA-256: de298d9917d07fdfef4ebc8b2aa3a8428b5d107d79d8b2109fe870faec9321f7
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF document contains an embedded OLE object specifically identified as related to Equation Editor, triggering heuristics for CVE-2017-11882. The presence of \objupdate and \objdata sections indicates that the embedded object is designed to be activated, likely leading to arbitrary code execution. This is a common delivery mechanism for exploiting this vulnerability.

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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000a7.bin
731ca36ddea74146826d11e471f650a28004ec5480e8f9a6de49a3b29ad7d266
rtf-objdata-decoded RTF \objdata at offset 0xA7 2125 bytes