Malicious RTF — malware analysis report

Static analysis result for SHA-256 1fc3df16f1119e35…

MALICIOUS

RTF

1.70 MB
MD5: 63443363f6d0b4b417a0a6dccd826dd4 SHA-1: 36e3628e7707b73c29ced4ab6e2ab1939d2ef1f2 SHA-256: 1fc3df16f1119e35ca14a5fcc24e0dc05aca38fd4276333a71e2b05acff1d580
220 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF file contains an OLE object associated with Equation Editor, strongly indicating exploitation of CVE-2017-11882. The presence of large amounts of hex-encoded data within the OLE object suggests it is used to hide a malicious payload. No specific family could be identified, but the attack pattern is clear.

Heuristics 5

  • Equation Editor OLE1 native payload — CVE-2017-11882 related critical CVE related CVE_2017_11882_RELATED
    RTF decodes to an OLE1 Equation.3 embedded object whose native data is large and payload-like, and \objupdate requests automatic activation. This is the delivery shape used by Equation Editor RCE documents such as CVE-2017-11882/CVE-2018-0802, but the malformed MTEF record needed for exact 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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1774KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001038.bin
ebcd604ca82c3a5bbedba3866d1a134a61d23be3f0df1ff0f0103ffc20210864
rtf-objdata-decoded RTF \objdata at offset 0x1038 887293 bytes