Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 bc2775183c5fc354…

MALICIOUS

RTF / .DOC

21.4 KB
MD5: 7c64cf6edb64f6c790b3c4d90142c224 SHA-1: f488d713238f4c2861b2931d38001ece9952a487 SHA-256: bc2775183c5fc354aaa7d28b9767859e1a12a8c1ffd46781511146de470c5c3c
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF document contains embedded OLE object data and specifically triggers the Equation Editor vulnerability (CVE-2017-11882). This exploit is designed to allow arbitrary code execution when the document is opened. The embedded object data is likely a payload designed to be executed by the exploit.

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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000c44.bin
bea5b20fb481020aaf01a36d22b0e70b8dcca3c27b1db1bdc02953c790cd0491
rtf-objdata-decoded RTF \objdata at offset 0xC44 1772 bytes