Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 93501266c14fefdf…

MALICIOUS

RTF / .DOC

3.3 KB
MD5: 4d17ca2791dd2912d94cc97ded5da97d SHA-1: 492fb0e1c1ab177ff8201fc3abd303eb48d7670e SHA-256: 93501266c14fefdf79f3e52ce6fb143a868da2607585bcf02d92b271dd61d54f
180 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object specifically targeting the Equation Editor vulnerability (CVE-2017-11882). The presence of ".objdata" and ".objupdate" sections, along with the critical RTF_EQUATION_EDITOR heuristic, strongly indicates exploitation of this known vulnerability. This technique is commonly used to deliver a secondary payload.

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_off000000a6.bin
514d94043ab290d76c082fba5162c9b2f80e862adf01dcae53a4b4a600f960bd
rtf-objdata-decoded RTF \objdata at offset 0xA6 1492 bytes