Malicious RTF — malware analysis report

Static analysis result for SHA-256 99f323df466b83b3…

MALICIOUS

RTF

11.1 KB First seen: 2020-09-24
MD5: 3d5abc66469a2c34ced4af18757fee74 SHA-1: 5de1d8d1885aae341551af9ae18e1c91f0b34895 SHA-256: 99f323df466b83b3c7e58076b8d10849ad5f8f23accd3854a07e2f141ea8d8c6
180 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that exploits CVE-2017-11882 through the Equation Editor. This vulnerability allows for arbitrary code execution, likely to download and run a secondary payload. The presence of the Equation Editor ProgID 'EqUatiON.3' is a strong indicator of this exploit.

Heuristics 5

  • Split hex Equation Editor ProgID + OLE object critical CVE likely 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.
  • 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 1 \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_off000018a4.bin rtf-objdata-decoded RTF \objdata at offset 0x18A4 1780 bytes
SHA-256: 8316e9f0fa55dacccc9cb2917d4cbd5a07a0c01173be675f1badb8f8ad9be0b9

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