Malicious RTF — malware analysis report

Static analysis result for SHA-256 e697f95228dc774f…

MALICIOUS

RTF

177.7 KB Authoring application: Riched20 6.3.9600 First seen: 2021-06-17
MD5: a105a5e83a0d068ca7b62cc189129275 SHA-1: 02e02371704782290a023b7e200ed7dff5aa8f96 SHA-256: e697f95228dc774facf4970040541b388583d10b1abc8b8ab9b2147eed17c19c
240 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object specifically identified as Equation Editor, triggering critical heuristics related to exploitation. The ClamAV detection name 'Rtf.Exploit.CVE_2018_0802-6624871-1' strongly suggests exploitation of CVE-2018-0802, a known vulnerability in Microsoft Equation Editor. This technique allows for arbitrary code execution upon opening the document, likely delivered via spearphishing.

Heuristics 6

  • ClamAV: Rtf.Exploit.CVE_2018_0802-6624871-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2018_0802-6624871-1
  • Equation Editor object class critical RTF_OBJCLASS_EQUATION
    Object class 'equation.3' references Equation Editor
  • Equation Editor ProgID + OLE object high RTF_EQUATION_EDITOR
    RTF references Equation.3 ProgID alongside \objdata — likely Equation Editor (CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798) but without the binary CLSID payload, so flagged at HIGH instead of CRITICAL.
  • \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_off00000100.bin rtf-objdata-decoded RTF \objdata at offset 0x100 7990 bytes
SHA-256: 1b2814242628f9e22a697fcaaca750fd4a6df43a60e6b7c98e894824f1355ee0

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