Malicious PDF — malware analysis report

Static analysis result for SHA-256 e2bb9168c81268da…

MALICIOUS

PDF

427.7 KB Created: 2008-09-14 18:25:45 -05:00 Authoring application: Writer (via OpenOffice.org 2.2) First seen: 2014-02-03
MD5: a36b3a5c442fee2d75598087319fbba5 SHA-1: d49da7b2569718fac85da30b8bef9b3b9638faf5 SHA-256: e2bb9168c81268daefd4eae2b12cd78e30f69ecd270b22969ff07dd6c0895267
536 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1566.001 Spearphishing Attachment T1059.001 PowerShell T1204.001 User Execution: Malicious Link T1059.003 Windows Command Shell

The PDF file contains embedded JavaScript and a Windows executable payload. The critical heuristic PDF_LAUNCH_COMMAND indicates that the sample attempts to execute 'cmd.exe' with specific parameters, likely to launch the embedded payload. The embedded file 'Vila.pdf' is declared as a PDF but is detected as a Windows executable by ClamAV, indicating a masquerading attempt. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 12

  • Adobe Reader Launch action command execution critical CVE exact CVE_2010_1240
    PDF uses the Adobe Reader/Acrobat Launch action pattern associated with CVE-2010-1240: cmd.exe is invoked with attacker-controlled parameters, paired with an embedded/exported payload.
  • ClamAV: Pdf.Tool.Agent-1388586 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Tool.Agent-1388586
  • Launch action critical PDF_LAUNCH
    PDF contains a /Launch action whose target is an executable, URL, or UNC path — can start an external application
  • Embedded Windows executable payload in PDF stream critical PDF_EMBEDDED_PE_PAYLOAD
    PDF stream bytes contain an embedded Windows executable with a verified PE header. Exploit chains often hide droppers inside ordinary streams rather than standard /EmbeddedFile attachments.
  • /Launch action target: cmd.exe critical PDF_LAUNCH_COMMAND
    PDF /Launch action specifies an executable target with parameters '/Q /C %HOMEDRIVE%&cd %HOMEPATH%&(if exist "Desktop\\Vila.pdf" (cd "Desktop"' — references a known-dangerous executable (cmd, PowerShell, etc.).
  • Embedded attachment masquerades: declared document, content is windows-executable critical PDF_EMBEDDED_FILESPEC_CONTENT_MISMATCH
    An /EmbeddedFile attachment's declared filename extension or /Subtype MIME type contradicts the magic bytes of its decompressed content. The attachment is declared as a benign document or image but the bytes are an executable or executable-bearing archive. This is a deliberate deception used to hide droppers in PDF attachments and is a generic indicator of embed-and-drop weaponisation, independent of any specific CVE.
  • /Launch action paired with attachment-dropping JS API high PDF_LAUNCH_PLUS_DROPPER_JS
    PDF combines a /Launch action with a JavaScript API call that writes or opens an attached/external resource — the canonical shape of the CVE-2010-1240 /Launch + exportDataObject family. Benign PDFs do not pair these surfaces; the combination indicates a drop-and-execute chain regardless of the specific JS API knobs or /Launch target.
  • Suspicious extracted artifact medium 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.
  • JavaScript action low 1 related finding PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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.monotype.comhttp://www.monotype.com/html/type/license.html In extracted file (stream_043_off0003b47c.bin)
    • http://www.monotype.com/html/mtname/ms_timesnewroman.htmlhttp://www.monotype.com/html/mtname/ms_welcome.htmlNOTIFICATIONIn extracted file (stream_043_off0003b47c.bin)

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Vila.pdf pdf-embedded-file PDF EmbeddedFile object 147 at offset 0x48B99 327264 bytes
SHA-256: abe3c7d73390a4a86e9f0ba1399a20ed42417a7e84d3879e290e112d1e49159a
Detection
ClamAV: Win.Exploit.DCOM-5
Obfuscation or payload: likely
actual_type=PE; declared_or_context_type=PDF; filename=Vila.pdf; kind=pdf-embedded-file Static shellcode analysis found candidate code region(s). Indicators: NOP sled, SC_GETPC_CALL, SC_STR_SHELLEXEC Static shellcode analysis recovered API/import strings: kernel32.dll, shell32.dll, KERNEL32.DLL, ShellExecuteA, LoadLibraryA, GetProcAddress
javascript_obj0148_000.js pdf-javascript-stream PDF /JS object 148 at offset 0x6AAC2 53 bytes
SHA-256: 9718c3ba0223dec1227909c221d6a1d85697e09231714572dcca71b8535cfd07
Preview script
First 1,000 lines of the extracted script
this.exportDataObject({ cName: "Vila", nLaunch: 0 });
stream_043_off0003b47c.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x3B47C 49632 bytes
SHA-256: 9b88735a0958fd603abc77eb2b296ec158360375a54ededb687110fdd2b4c4bb
font_00_sfnt_off0003330a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3330A 50456 bytes
SHA-256: d1c2007ccb2b96250f1c535bb87fd1add919f763e2f99129b50584112106fa8e
font_02_sfnt_off00042dc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x42DC7 26376 bytes
SHA-256: 8a035528e6ea658aec30f66a444d2d9eaff9fdab1e5ffefa9a0f0cef0799bab6