Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 048212b79541c64f…

MALICIOUS

RTF / .DOC

19.4 KB
MD5: a309908b4fbebca58f35239697acfe99 SHA-1: 51e6b7958e3cedb8774f4ad2f28fb82fc21e3295 SHA-256: 048212b79541c64fd9546a04c00400db77a3f09bebed3731a57a6f03435f1d8a
120 Risk Score

Malware Insights

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

The sample is an RTF document that contains embedded OLE object data, specifically targeting the Equation Editor vulnerability. The \objupdate directive indicates that the embedded object will be activated, leading to exploitation. This technique is commonly used to download and execute a second-stage payload, hence the high confidence in this 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000011ba.bin
d53a9cff2ec737877972d5e99aa71bed827e580b1b62ed5c2a4be6a7d2e9f92a
rtf-objdata-decoded RTF \objdata at offset 0x11BA 1382 bytes