Malicious RTF — malware analysis report

Static analysis result for SHA-256 ca80938715ed9886…

MALICIOUS

RTF

9.4 KB First seen: 2020-02-04
MD5: 110920778b09d04ecca9d0548cfd7752 SHA-1: ab92eeee9262b4877832164b3a4ff5e78bc0c362 SHA-256: ca80938715ed9886604daf7caeca1e74f1024c7ce070c06ac24140bf59a817a9
180 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that triggers the CVE-2017-11882 vulnerability in Microsoft Equation Editor. This vulnerability allows for arbitrary code execution, indicating the file is designed to exploit this flaw. The presence of the ".objupdate" directive further suggests an attempt to activate the embedded object. Given the nature of the exploit, it is likely delivered as a spearphishing attachment.

Heuristics 4

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000032.bin rtf-objdata-decoded RTF \objdata at offset 0x32 4669 bytes
SHA-256: e8d1a7b43731569e15d7e57a776b3f7760777f380b7e34dfc4398bce53959157