Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 494f8a8435b0d8c7…

MALICIOUS

RTF / .DOC

33.0 KB First seen: 2022-12-12
MD5: fffa4d76a568e62cbc88934459a2ae09 SHA-1: f4c180643ef97241db8a4e05cef292769e77a3f3 SHA-256: 494f8a8435b0d8c7599d340801e9e11c5f17ffee415ccd1e2e848d9c1cee6d24
200 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 (CVE-2017-11882). The document body includes a lure instructing the user to 'Enable editing', a common tactic for macro-based malware. The embedded OLE object is designed to be activated upon opening, leading to the execution of a secondary payload.

Heuristics 6

  • 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 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off000054cc.bin
2621fbc46a1f8eceb95dc4700e99ddf08df69b601bf7741b110d111fb250ae01		 rtf-objdata-decoded RTF \objdata at offset 0x54CC 1820 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.