Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ae489ddc3a31dc1a…

MALICIOUS

RTF / .DOC

4.5 KB
MD5: 03952d1465af4520f13d1848d50a56f6 SHA-1: c578f8635cbce52579792a015d10d6e53fccb261 SHA-256: ae489ddc3a31dc1a5c6c10c3939a0e8efe37edb5695e9e68a9411db09ad7d812
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The sample is an RTF document containing embedded OLE objects, specifically triggering the CVE-2017-11882 vulnerability related to Equation Editor. This exploit is known to allow for arbitrary code execution upon opening the document. No further stages or IOCs were identified in the static analysis.

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_off000000e2.bin
b18ac71e3b326e0c33979c5d71a99beb64f9b30b8af69ed1d51ab07241243993
rtf-objdata-decoded RTF \objdata at offset 0xE2 1964 bytes