Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 10a930d98bea75fd…

MALICIOUS

RTF / .DOC

4.0 KB
MD5: f76f1ab1f9937b0fc49f96eb9bfa1b17 SHA-1: f7382cfe962b404647a8da3a527356002bc938b8 SHA-256: 10a930d98bea75fd95e52535e9195bc783e175b066340e037c9d0ce341cbf229
180 Risk Score

Malware Insights

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

The RTF file contains embedded OLE objects, specifically triggering heuristics related to Equation Editor and CVE-2017-11882. The presence of ".objupdate" indicates that the embedded object is forced to activate, leading to the exploitation of the Equation Editor vulnerability for client execution. This is a common method for delivering malicious payloads.

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_off000000d3.bin
ac0dd8e2d171698088efe56f466d47849b8fe03e273821bef2f2d92b753162db
rtf-objdata-decoded RTF \objdata at offset 0xD3 1771 bytes