Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 103d958c754c80a5…

MALICIOUS

RTF / .DOC

16.0 KB
MD5: 3a7663635d1e0c1adf95010ee590994a SHA-1: a5d6cdeaaa0be6d75bf2c5cfcbe1bc335d1cb0d3 SHA-256: 103d958c754c80a59ab3284b0dfff80e2edf6e9c7373aeda103df0502a533b2f
180 Risk Score

Malware Insights

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

The sample is an RTF document containing embedded OLE object data, specifically triggering heuristics related to Equation Editor and CVE-2017-11882. This indicates the document is designed to exploit this vulnerability for code execution. The presence of `EquatioN.3` as a ProgID is a key indicator of this exploit.

Heuristics 5

  • Obfuscated Equation Editor ProgID + activation critical CVE related RTF_EQUATION_EDITOR
    RTF decodes to an Equation.3 ProgID from top-level \objdata hex after nested RTF junk groups are ignored, and the document also contains \objemb plus \objupdate activation. This is an obfuscated Equation Editor exploit surface associated with CVE-2017-11882 / CVE-2018-0802 families, but no exact malformed MTEF CVE primitive was recovered from this object.
  • 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.
  • \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_off000017d3.bin
cf57db133125dba46d7e122721cf0d80da493a4398de0a373c07efea4574e3ab
rtf-objdata-decoded RTF \objdata at offset 0x17D3 1545 bytes