Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3259507735578bc…

MALICIOUS

PDF

75.7 KB Created: 2021-09-01 07:07:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ddb8cb3042d69ad281d5ea7224e2034f SHA-1: 3179389737ef06f36ac043e5750c8ea5bb98c291 SHA-256: a3259507735578bc45751e686b75df68ed693d9b3666e47b8009e363f6ca03c8
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains a callback phishing lure, instructing the user to call a phone number regarding a fabricated issue. While no scripts were directly extracted, the presence of multiple links to potentially compromised WordPress sites and a link farm structure suggests an attempt to host malicious content or redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://musorcentrum.hu/files/article/file/fagasisagurolugilivilozu.pdf In PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca5c1c17694---rimurolumizodo.pdfIn PDF document text
    • http://www.psyforyou.nl/upload/fckeditor/file/mazuwoteworabo.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/xegojifokipi.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a92ac269aed---pozotakapijemusuxutufiton.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/f95a9e43f1d6ad2a772c637a8d1e163a/47946030519.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612dc34a2b656---31987175579.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-5-5/20210505102739275518.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/160d77e6806fa3---43076104376.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/kumobufiwegodevo.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/qranre95dia9p0n9qjii9to9c5/tixaruluteku.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/446b291216f05c76d85300b507aadd08/87506356050.pdfIn PDF document text
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/grsea90f23cumidktu0lvnq3jg/76976403697.pdfIn PDF document text
    • https://amgaa.org/temp/files/98037000682.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160ae9e0e2c9c1---23032153028.pdfIn PDF document text
    • https://autoprofi.ua/userfiles/file/difuvanizasufeponufajemu.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/89478453837.pdfIn PDF document text
    • https://ciar.vn/uploads/image/files/texepuriz.pdfIn PDF document text
    • https://www.chesapeake-lighting.com/wp-content/plugins/super-forms/uploads/php/files/ffe394078a0703306aa2a3ded3533150/gatujurafivuwagomobuseg.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/4a63421d3fb1c2d278159808f6d12b09/9887504284.pdfIn PDF document text
    • https://samsungvrvklima.com/upload/ckfinder/files/77982973812.pdfIn PDF document text
    • https://honghow.com/ckfinder/userfiles/files/3859661739.pdfIn PDF document text
    • https://talleresimad.com/images/subidas/files/8420863261.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=how+to+find+axis+of+symmetry+in+intercept+formPDF 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_off0000c39c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC39C 11028 bytes
SHA-256: d17bafb8cd0f55920f06c3164e17522e756883b484ea9b15d40ff0c41fe88f51
font_01_sfnt_off0000dd4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f55e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF55E 17056 bytes
SHA-256: 11b54db86c47105927c2e8fe2fd1c955b21444d15bbee22858a1a9f703f0daf0