Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4c31a6f36906724…

MALICIOUS

PDF

69.2 KB Created: 2021-09-20 13:48:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: adf72f5df10b4549fe8d3a626f63f750 SHA-1: 676f4d3c1212d0c6dcfda96c30e306830a1b9e8f SHA-256: c4c31a6f3690672415fbc77c5b550772a0563c20dfc458aa19142d146494e234
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware via the link farm. The presence of JavaScript suggests an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • 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.
  • 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://centonze-vini.com/userfiles/files/tikugodowexurekejukupula.pdf In PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/41333767438.pdfIn PDF document text
    • http://tg-focus.ru/userfiles/files/91406309091.pdfIn PDF document text
    • https://pfhotel.gr/ckfinder/userfiles/files/rajap.pdfIn PDF document text
    • http://simsoncantho.com/userfiles/file/43734200966.pdfIn PDF document text
    • http://osstemcardiotec.com/files/fckeditor/file/20737350866142ffb5c3f26.pdfIn PDF document text
    • http://kiajihlava.cz/UserFiles/File/25449392752.pdfIn PDF document text
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/pewunamamineletejuririxi.pdfIn PDF document text
    • http://tufaghanafc.com/js/ckfinder/userfiles/files/8961990218.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143af31a663c---82977561184.pdfIn PDF document text
    • https://resicolor.com/upload/files/nepiruwilirenuxukunodel.pdfIn PDF document text
    • https://freshchannels.com/home/sites/freshchannels/public_html/ckfinder/userfiles/files/tagorazibozuzolajep.pdfIn PDF document text
    • https://whiteplacard.com/UserFiles/file/39246810006.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/trd6l0npkff0cijf2ibukfot9f/bijozazijafanu.pdfIn PDF document text
    • http://chukgoobok.com/files/fckeditor/file/64081638641.pdfIn PDF document text
    • http://xn--80aatg4aaaddkhfhbf3evf.xn--p1ai/ckfinder/userfiles/files/zalulafet.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/c17bd7646a3a083014f44ecef6782cc3/47277970986.pdfIn PDF document text
    • http://yongqingtech.com/d/files/5219646763.pdfIn PDF document text
    • https://petribax.com/userfiles/file/67533258178.pdfIn PDF document text
    • http://cbgnfinance.com/userfiles/file/31369137966.pdfIn PDF document text
    • http://hyundainhapkhau.net/upload/files/fodokirilibipit.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=clash+of+clans+paradise+apk+downloadPDF 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_off0000ae64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE64 15836 bytes
SHA-256: 520dfb02aade84592849a61b6abf0f7427cb52d76343193cabf1e365ede8dcb3
font_01_sfnt_off0000d6b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6B6 10828 bytes
SHA-256: 947c2a8639825e567f9763eae4766fec6695e5cc4acee27ed46da335118d802d
font_02_sfnt_off0000efaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1