Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f5c015d4e4e2112d…

MALICIOUS

RTF / .DOC

15.8 KB
MD5: 1ff2867813d4a0f7d7aca4b831cdee3c SHA-1: 0bcc002ad4e3b4c0c0770017709f403c5a2bad15 SHA-256: f5c015d4e4e2112d6e62b8cd4852e4cbb700aa4df7cf4c2eb56069041d257c64
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF file contains multiple indicators of exploitation for CVE-2017-11882, specifically related to the Equation Editor. The presence of OLE objects and the ".objupdate" directive strongly suggest that the embedded Equation Editor object is designed to be activated, leading to arbitrary code execution. This is a common delivery mechanism for exploiting this vulnerability.

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_off00002041.bin
e95d8cf74c26cbd7d95f97f488a0064f4328dcec9332431c146fcfe542b70007
rtf-objdata-decoded RTF \objdata at offset 0x2041 1952 bytes