Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 0d99e4d69e2e6f5d…

MALICIOUS

RTF / .DOC

34.7 KB
MD5: 01e758570ef71042a1cd1703d8dfed27 SHA-1: 9123da962b12908b10744c9ea24194e9260fd657 SHA-256: 0d99e4d69e2e6f5dffbdb2bd1177caa38ebaa50af35a461f16c0ee3a77d90e41
120 Risk Score

Malware Insights

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

The sample is an RTF document that contains OLE object data and specifically targets the Equation Editor vulnerability. The ".objupdate" directive forces the OLE object to activate, triggering the exploit. This technique is commonly used to download and execute a secondary payload, hence the high confidence in this attack pattern.

Heuristics 3

  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001edc.bin
9212c11666c933f04a77ab5673c7c8c5269a096288458204cb8796c2d8c7f141
rtf-objdata-decoded RTF \objdata at offset 0x1EDC 9795 bytes