Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a33158aba13143d…

MALICIOUS

PDF

66.5 KB Created: 2021-09-25 07:50:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 4ce6c405cb6a0c906edfb277a57811e7 SHA-1: 51b5ca77cf3cf3d1387d5cc09da11620c96a8bf8 SHA-256: 9a33158aba13143d28ee53ac5ce9b7a191ad10df76e11bac8f55a897468060a0
124 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a PDF containing a link farm, with multiple heuristics indicating it points to compromised CMS uploads and disposable hosting. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports a malicious intent. Although no scripts were explicitly extracted, the nature of link farms in PDFs often involves JavaScript to redirect users, hence T1059.007 is included. The primary goal appears to be directing users to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.4625

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://pk.mo/userfiles/file/zulugogake.pdf In PDF document text
    • https://lensprovn.com/ckfinder/userfiles/files/koref.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/23ee0a896db8017260c5b08bec612cea/7065117300.pdfIn PDF document text
    • http://zabbeleecooking.com/ckfinder/userfiles/files/13814213117.pdfIn PDF document text
    • http://sporteambiente.it/ckfinder/userfiles/files/45679666270.pdfIn PDF document text
    • http://charivne.info/images/file/12670275330.pdfIn PDF document text
    • https://girl0229960192.com/upload/users/files/84829526534.pdfIn PDF document text
    • http://www.skk.com.hk/admin/ckfinder/userfiles/files/74468749554.pdfIn PDF document text
    • http://mrtowing.ca/Lawyers/userfiles/file/fufoxagebidusite.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/gurevonafekufetedud.pdfIn PDF document text
    • http://akcihlar.cz/userfiles/file/96238193973.pdfIn PDF document text
    • http://disonde.com/filespath/files/20210910175924.pdfIn PDF document text
    • http://surveycook.com/upload/tmp/202109/file/96366307754.pdfIn PDF document text
    • http://hit-air.pro/ckfinder/userfiles/files/94183410019.pdfIn PDF document text
    • https://degardo.hollandpazsit.hu/ckfinder/userfiles/files/79980551318.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16136898464ccf---37891200916.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16139a901430ff---59876707188.pdfIn PDF document text
    • http://agedwedfjtj.pretty-match.com/upload/files/vafawudupoganuw.pdfIn PDF document text
    • http://projecthouse.bg/uploads/CKfinder/files/31463649599.pdfIn PDF document text
    • http://4rrecycle.com/files/file/96631268814.pdfIn PDF document text
    • http://stmrcstvm.com/userfiles/file/17785110875.pdfIn PDF document text
    • http://damosushipleasanthill.com/uploads/files/62442604887.pdfIn PDF document text
    • http://futboltotal.net/images/files/guvigewunuwo.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/ng1d03tnih9ecjffs8n2nvppib/borozaxupamalukun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=how+to+block+proxy+sites+in+androidPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c066.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC066 18744 bytes
SHA-256: 298d94a1f8062b4b9251e8f5c366828dd4ea747877f29319c852e95c301dd3c3
font_01_sfnt_off0000f0d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1