Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b9e77b8050d7a131…

MALICIOUS

RTF / .DOC

84.1 KB
MD5: d047e64a2b3cf66d168e0af3b25eba0f SHA-1: a2a0d2322a8e6793c4dc4556f52090a3b4abdd6e SHA-256: b9e77b8050d7a131ecfbb21e68e6300df0d75579fae917b6a0859469b3869808
120 Risk Score

Malware Insights

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

The sample is an RTF document that contains embedded OLE object data, specifically targeting the Equation Editor. The \objupdate directive indicates that the embedded object will be activated automatically upon opening. This strongly suggests an exploit targeting the Equation Editor vulnerability (CVE-2017-11882), which is commonly used to deliver secondary payloads. No specific family could be identified, but the attack pattern is consistent with exploit-laced documents.

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_off00000fd3.bin
b3f7148972dfa491e5460354298663ed0d15c12bc6644c997afab0abc03c74bd
rtf-objdata-decoded RTF \objdata at offset 0xFD3 1927 bytes