Malicious RTF — malware analysis report

Static analysis result for SHA-256 5484e0c37d05b61e…

MALICIOUS

RTF

888.3 KB First seen: 2022-09-29
MD5: 3b0c2c46229a9d4481191db64b946de3 SHA-1: 623b9af2cd76140b8a7c1332becfdd53c5215238 SHA-256: 5484e0c37d05b61e086fc6242103bfda3901f033e75bccb991dbf52c1349f67a
180 Risk Score

Malware Insights

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

The RTF file contains multiple heuristics indicating the exploitation of CVE-2017-11882 through an embedded OLE object, specifically identified as Equation Editor. The ".objupdate" directive forces the activation of this embedded object, which is a known method for arbitrary code execution. The presence of OLE object data and the specific Equation Editor ProgID strongly suggest this exploit vector.

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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000012b8.bin
6104ca9e2637c107baaa65c53042f5bf976dc9d7b973236889d8fec466064371		 rtf-objdata-decoded RTF \objdata at offset 0x12B8 86537 bytes
objdata_01_off0003561b.bin
3191c7b669a99e6dbec6e45083f1ba3cae1925f2a91f1d3c51265214befb2f16		 rtf-objdata-decoded RTF \objdata at offset 0x3561B 141152 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.