Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb378811b52c96db…

MALICIOUS

PDF

72.4 KB Created: 2021-09-14 13:43:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 80fe33173e3a82fca723caa429c90a87 SHA-1: d393b9ce6b8471d8faec8b336fe580526770eaf9 SHA-256: cb378811b52c96db28dddefea42312d7d520eb05de5d9f67f074c27b23713b76
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ML classifiers and ClamAV, exhibiting characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous links pointing to potentially compromised websites and disposable hosting, suggesting an attempt to lure users to malicious content. The presence of external URIs and link farm patterns strongly suggests a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://liqaa-lb.com/files/userfiles/files/goxipexa.pdf In PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1631282069.pdfIn PDF document text
    • http://career-id.org/ckfinder/userfiles/files/dewukosodolupubusaraxuke.pdfIn PDF document text
    • http://tcyy88.com/userfiles/file/2021090312334273499.pdfIn PDF document text
    • https://alkathirilaw.com/userfiles/files/nipubawone.pdfIn PDF document text
    • http://monikaknoblochova.com/userfiles/file/56965915132.pdfIn PDF document text
    • https://vpmemorial.net/images/file/kosovib.pdfIn PDF document text
    • https://oancora.com/ckfinder/files/23387089829.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/jipapesejitisilusu.pdfIn PDF document text
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/92918713129.pdfIn PDF document text
    • http://theonejsc.com/userfiles/file/fozatejapodu.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7d2e61cbe---73038763165.pdfIn PDF document text
    • https://datajournonepal.org/files/gozotomaja.pdfIn PDF document text
    • http://mitchelllawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/71968957159.pdfIn PDF document text
    • https://verticala.ro/images/userfiles/jexamanoma.pdfIn PDF document text
    • http://rayocazar.com/images/elfinder-1.1/files/file/faxujewurog.pdfIn PDF document text
    • http://kccmaul.com/files/files/74691886009.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613145517191b---xidaki.pdfIn PDF document text
    • http://thermcom.cz/userfiles/file/15494787012.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/8559d53a567ba0e65869d11f46604dcf/jelugimexusonitufi.pdfIn PDF document text
    • http://toszegisuli.hu/userfiles/file/kifepegolasuwerovid.pdfIn PDF document text
    • http://sellmysayarah.com/userfiles/files/71207281221.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/gopef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=office+portal+365+adminPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b71d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB71D 11112 bytes
SHA-256: 3e25a25da043893b7f5760eb1b88772b4fd1a7c30c02b265239bd1f4e9196c74
font_01_sfnt_off0000d105.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD105 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e917.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE917 16788 bytes
SHA-256: 775573492caf3e9dec9ab069d9d2f17abda65a85eedb027dce7373243ada6e81