Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a4f6208cdb712aa…

MALICIOUS

PDF

413.9 KB Created: 2005-12-07 12:19:12 +01:00 Authoring application: Writer (via OpenOffice.org 2.0) First seen: 2015-10-13
MD5: bf916a13b6dcf6c0526e07168a057810 SHA-1: 8f75ae7fa204b81338756b7663e7e7a4905af2e2 SHA-256: 7a4f6208cdb712aa9c9f583802ceacc46abce3e4e44d5b6e1cb09174ef9ae5d3
618 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript that uses the `exportDataObject` function to launch `cmd.exe` and execute a file named 'Manual_netcat.pdf'. This executable is likely a second-stage payload, as indicated by the critical heuristic 'PDF_EMBEDDED_PE_PAYLOAD' and ClamAV detection on the extracted artifact. The document body's description of Netcat and the embedded filename 'Manual_netcat.pdf' suggest a lure to download and execute a tool, which is then used for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 15

  • 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\\Manual_netcat.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.
  • Clickable PDF combines external action with parser-evasion structure high PDF_ACTION_PARSER_EVASION
    PDF has an external clickable URI together with object graph or xref structures that make parsers disagree, such as divergent duplicate objects, parser divergence, or xref offset mismatch. That combination is stronger than a plain link: the document is both an outward-action carrier and a parser-confusion/evasion sample.
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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.zeustech.net/ Referenced by PDF JavaScript
    • http://]hostname[:port]/pathIn extracted file (Manual_netcat.pdf)
    • http://www.monotype.comhttp://www.monotype.com/html/type/license.htmlIn extracted file (stream_021_off00053832.bin)
    • http://netcat.sourceforge.net/PDF link annotation
    • http://www.apache.org/Referenced by PDF JavaScript
    • http://www.monotype.com/html/mtname/ms_arial.htmlhttp://www.monotype.com/html/mtname/ms_welcome.htmlNOTIFICATIONIn extracted file (stream_021_off00053832.bin)
    • http://www.monotype.com/html/mtname/ms_couriernew.htmlhttp://www.monotype.com/html/mtname/ms_welcome.htmlNOTIFICATIONIn extracted file (font_00_sfnt_off0003ea14.bin)

Extracted artifacts 9

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Manual_netcat.pdf pdf-embedded-file PDF EmbeddedFile object 83 at offset 0x5C61C 73802 bytes
SHA-256: 7a354006cadc485228abd0a1b464ec7a62e1c6ccec1316b6e99bc001ae031b2c
Detection
ClamAV: Win.Trojan.MSShellcode-7
Obfuscation or payload: likely
actual_type=PE; declared_or_context_type=PDF; filename=Manual_netcat.pdf; kind=pdf-embedded-file Static shellcode analysis found candidate code region(s). Indicators: SC_PEB_ACCESS, SC_MSF_REVERSE, SC_PUSH_STRING Static shellcode analysis recovered API/import strings: kernel32.dll, advapi32.dll, KERNEL32.DLL, ADVAPI32.DLL, LoadLibraryA, GetProcAddress
javascript_obj0084_000.js pdf-javascript-stream PDF /JS object 84 at offset 0x6726B 62 bytes
SHA-256: 8adf29475267a5950b7867122d7878890d1c53d1ffea3745107973374d2fa733
Preview script
First 1,000 lines of the extracted script
this.exportDataObject({ cName: "Manual_netcat", nLaunch: 0 });
stream_010_off0002d91e.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x2D91E 433566 bytes
SHA-256: 34fa7c0d5291ba1f4f29bd7176c6c415c407dded508044372865e9d4c0b648b3
stream_012_off000368ba.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x368BA 348192 bytes
SHA-256: dd37f4dd41036a94b9deed246a5f0c9fd24bbc29ef24279a66bc2fdf18c62eae
stream_021_off00053832.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x53832 45924 bytes
SHA-256: 48dde9445b3e9aa063e63adf62f233e6b1f143b5a7e8a46e4ca46716d78580b8
font_00_sfnt_off0003ea14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3EA14 44544 bytes
SHA-256: 2a9bb1a7d8f5ebf83fe15b772d29d2bdf0a184d43d062e954c20a9280a4156eb
font_01_sfnt_off00045643.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x45643 35788 bytes
SHA-256: 2af4aeba68d001e1d58100984662fab05a798d19fb97280c13e69bc087933457
font_02_sfnt_off0004a6db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4A6DB 27688 bytes
SHA-256: 1dd7db2dc9b6c6139a22038e2b0728cb06985841b9a2ffcc9b8705c6a3266053
font_03_sfnt_off0004e308.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4E308 36120 bytes
SHA-256: d1bba42d08b71772e54326fecfb9a7f41c831c5e2e3bfb99ec3678c79c0cc30a