Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fb98fa806e60622…

MALICIOUS

PDF

69.0 KB Created: 2021-10-02 12:33:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a892611a9a0bac4c096d89307179ed12 SHA-1: ba45fcd7e5b4bcbde0c9c819cc939adb9778ae89 SHA-256: 8fb98fa806e606223271d389645d0d48446c4cd54bff8a5ea29d70d6e3bb3658
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The presence of multiple PDF link farm heuristics reinforces the conclusion that this document is part of a campaign to drive traffic to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://2015.letnifestiwal.pl/ckfinder/userfiles/files/tukulewizojatiwejix.pdf In PDF document text
    • http://cdkuys.handysociality.com/upload/files/8549702535.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137613445ac6---fuvigewefofasa.pdfIn PDF document text
    • http://archive-2013.humandoc.pl/attachments/file/88164665581.pdfIn PDF document text
    • http://orsini-blasioli.it/userfiles/files/9996635041.pdfIn PDF document text
    • https://alteanetworks.fr/img/file/xofetos.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/161363fe8b8590---17230394487.pdfIn PDF document text
    • https://kvzriu.org/images/file/mojebegeru.pdfIn PDF document text
    • http://realfootball.gr/userfiles/file/wasutoma.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/16152292d7c68e---52906643565.pdfIn PDF document text
    • https://accidentmatters.com/ckfinder/userfiles/files/23123060753.pdfIn PDF document text
    • http://arabstina.com/ckfinder/userfiles/files/66944121821.pdfIn PDF document text
    • https://hawkseyetravels.com/assets/ckfinder/userfiles/files/4713343684.pdfIn PDF document text
    • http://alefart.ru/admin/ckfinder/userfiles/files/wexutekidit.pdfIn PDF document text
    • http://riverhouse.at/pcms/content/file/5059869240.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/96057719281.pdfIn PDF document text
    • http://moto-bike.pl/userfiles/file/61564200696.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/4fdb162103915cca072a0ff5f7934341/zolomasovenonokizu.pdfIn PDF document text
    • http://musik-fachberatung-neumarkt.de/images/uploadedimages/file/zowom.pdfIn PDF document text
    • https://safrano.pl/userfiles/file/xerazulakozasomodotifi.pdfIn PDF document text
    • http://meskerjager.nl/media/files/14578022756.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=blue+merle+schnoodle+puppies+for+salePDF 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_off0000ab79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAB79 10940 bytes
SHA-256: 7ff5a4ea4da4e603cc96595c37471edcf57b21c2b01fea8d4635949318660c59
font_01_sfnt_off0000c491.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC491 15844 bytes
SHA-256: fe9815e8602b17e170ed180a5cf83cf4b603835d16fe162554d1e2395ee01d89
font_02_sfnt_off0000ecd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECD4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1