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)
MD5: bf916a13b6dcf6c0526e07168a057810 SHA-1: 8f75ae7fa204b81338756b7663e7e7a4905af2e2 SHA-256: 7a4f6208cdb712aa9c9f583802ceacc46abce3e4e44d5b6e1cb09174ef9ae5d3
556 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.003 Windows Command Shell T1105 Ingress Tool Transfer T1566.002 Spearphishing Attachment

The PDF file contains a critical PDF_LAUNCH heuristic firing, indicating a launch action. This action targets 'cmd.exe' with specific parameters, and a critical PDF_EMBEDDED_PE_PAYLOAD heuristic confirms an embedded Windows executable. The PDF_LAUNCH_PLUS_DROPPER_JS heuristic further indicates that a JavaScript API was used to drop the attachment, which is disguised as 'Manual_netcat.pdf'. The embedded executable was detected by ClamAV as 'Win.Trojan.MSShellcode-7'. The CVE_2010_1240 technique is directly matched by the PDF launch action and embedded payload chain.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 14

  • 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.
  • 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.
  • ClamAV: Pdf.Tool.Agent-1388586 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Tool.Agent-1388586
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • /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.
  • JavaScript action low 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://netcat.sourceforge.net/

Extracted artifacts 8

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Manual_netcat.pdf
7a354006cadc485228abd0a1b464ec7a62e1c6ccec1316b6e99bc001ae031b2c
pdf-embedded-file PDF EmbeddedFile object 83 at offset 0x5C61C 73802 bytes
Detection
ClamAV: Win.Trojan.MSShellcode-7
Obfuscation or payload: unlikely
javascript_obj0084_000.js
8adf29475267a5950b7867122d7878890d1c53d1ffea3745107973374d2fa733
pdf-javascript-stream PDF /JS object 84 at offset 0x6726B 62 bytes
stream_010_off0002d91e.bin
34fa7c0d5291ba1f4f29bd7176c6c415c407dded508044372865e9d4c0b648b3
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x2D91E 433566 bytes
stream_012_off000368ba.bin
dd37f4dd41036a94b9deed246a5f0c9fd24bbc29ef24279a66bc2fdf18c62eae
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x368BA 348192 bytes
stream_021_off00053832.bin
48dde9445b3e9aa063e63adf62f233e6b1f143b5a7e8a46e4ca46716d78580b8
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x53832 45924 bytes
font_00_sfnt_off00045643.bin
2af4aeba68d001e1d58100984662fab05a798d19fb97280c13e69bc087933457
pdf-font-stream PDF embedded font (sfnt) at offset 0x45643 35788 bytes
font_01_sfnt_off0004a6db.bin
1dd7db2dc9b6c6139a22038e2b0728cb06985841b9a2ffcc9b8705c6a3266053
pdf-font-stream PDF embedded font (sfnt) at offset 0x4A6DB 27688 bytes
font_02_sfnt_off0004e308.bin
d1bba42d08b71772e54326fecfb9a7f41c831c5e2e3bfb99ec3678c79c0cc30a
pdf-font-stream PDF embedded font (sfnt) at offset 0x4E308 36120 bytes