Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6f9120990c1bb87…

MALICIOUS

PDF

83.5 KB Created: 2021-08-12 06:20:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 191612c8dc8f47b938506c566d81f055 SHA-1: 0fbbf228d7bae561b8129a38f0e91299e6d3b246 SHA-256: c6f9120990c1bb87f651ccb1efb3ab78e4b855f448339bbee7e1c87c158af487
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised WordPress sites or disposable hosting. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool rather than user-readable content, suggesting the primary function is to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://www.allatpatikapecs.hu/images/file/97477221155.pdf In PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160d7922599f53---selavo.pdfIn PDF document text
    • http://stringpoets.com/userfiles/file/14527216764.pdfIn PDF document text
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/zalufoled.pdfIn PDF document text
    • http://www.retorika-zidar.si/ckfinder/ckeditor_uploaded_files/files/47594735504.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607b85a5b2c56---mipemejidikipup.pdfIn PDF document text
    • http://criminisiepartners.it/userfiles/files/xuwopovisebi.pdfIn PDF document text
    • http://bjallstar.com/upload/file/wofodepisawiramifegoximiw.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/fi19u7i4i3t433rv0p2gs23lt3/lovopu.pdfIn PDF document text
    • https://actor-conseil.com/files/file/41586449662.pdfIn PDF document text
    • http://cleangroupbd.com/ck/upload/files/numaserodiwokasifiwana.pdfIn PDF document text
    • http://hizlipin.com/calisma2/files/uploads/kewamibezebute.pdfIn PDF document text
    • https://lawina-radom.pl/files/file/11440982374.pdfIn PDF document text
    • http://kiuanai.com/userfiles/file/59582647768.pdfIn PDF document text
    • http://xn----7sbabjkhbzbqti4a3apfmdd2s4b.xn--p1ai/ckfinder/userfiles/files/89066749645.pdfIn PDF document text
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/8900809767.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/5l7h7mokvsmf3mm4of9devu44i/65936455099.pdfIn PDF document text
    • https://investmentskillsgroup.com/images/userfiles/file/24513757485.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/46050343749.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c07219d69f---39801311724.pdfIn PDF document text
    • http://johnsonsdynastyincfamilyassociation.com/clients/10108/File/40391465375.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/zeteberivojadada.pdfIn PDF document text
    • http://fujiya-la.com/uploads/files/10237614921.pdfIn PDF document text
    • http://fluellentrees.com/clients/58222/File/gakim.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=caracteristicas+estructurales+de+los+monosacaridosPDF 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_off0000e215.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE215 10664 bytes
SHA-256: e5228001f8b7cfd12541f93fd9360360601ba33f7aad5be405b5aab8b7eb5957
font_01_sfnt_off0000fa7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA7F 17344 bytes
SHA-256: 7ac267033e5232ebcd5fa49496542cad09ac0f0dae3a221b67a730f012f389e2
font_02_sfnt_off00012691.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12691 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1