Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 27d24a92dff06b32…

MALICIOUS

RTF / .DOC

35.4 KB First seen: 2022-10-13
MD5: 3d1a05bbb99d89c9fbf9c7475885f894 SHA-1: d72eb2d63a0b3cf68785355f4a860a14a001ebf6 SHA-256: 27d24a92dff06b3211d04c1eaeaee2b68d7196450b5842b53f7fa4a030d3b96c
200 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The file is an RTF document containing an embedded OLE object that exploits the Equation Editor vulnerability (CVE-2017-11882). The presence of RTF_EQUATION_EDITOR and CVE_2017_11882_ACTIVATION_RELATED heuristics strongly indicates this exploit. The SE_ENABLE_LURE heuristic suggests the document prompts the user to enable editing, a common tactic for macro-based malware delivery.

Heuristics 6

  • 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 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001e75.bin
a8dbc015c7d368a0e3d6227efef604bd460a71a24fa90dac4d94d5dad33e1428		 rtf-objdata-decoded RTF \objdata at offset 0x1E75 1888 bytes

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