Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3abdae2cdb03970d…

MALICIOUS

RTF / .DOC

32.2 KB First seen: 2022-12-05
MD5: 726c0201c5a5db97fde11dd2d3d22dce SHA-1: ce8d32b00118ef466427e6717dfa612b9f33b552 SHA-256: 3abdae2cdb03970de9fe48380e3c6dfd7e71d6716f72a4fb1de260dfe136b65e
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic to bypass macro security and trigger the exploit. The presence of ".objdata" and ".objupdate" sections further indicates the exploitation of embedded objects. The primary attack vector appears to be leveraging a known vulnerability via an embedded exploit.

Heuristics 4

  • 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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00005c16.bin
9c92685997ec201410557e7cd45b39320a549177f8d6ffda9073cb2d226b2c8f
rtf-objdata-decoded RTF \objdata at offset 0x5C16 1885 bytes