Malicious PDF — malware analysis report

Static analysis result for SHA-256 1635cc71c99f0744…

MALICIOUS

PDF

81.8 KB Created: 2021-09-17 14:20:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 87c22e123505b5128613202333f9c471 SHA-1: ceda2e81d458e83724a718d60c193cd54fc066f7 SHA-256: 1635cc71c99f07448b14b689bb631860e4380514e3278dce28b055e4c2a6d345
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains a link farm with numerous URLs, some pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to lure users to external sites, likely for credential harvesting or malware delivery.

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 https://goodline.by/userfiles/file/nilafuzesofojipibezafe.pdf In PDF document text
    • https://isitekmuhendislik.com/userfiles/file/40611994118.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613b6c5b52546---22747499020.pdfIn PDF document text
    • http://dostrojar.sk/UserFiles/file/jezenefos.pdfIn PDF document text
    • http://ventima.ru/userfiles/file/sonomurat.pdfIn PDF document text
    • http://wisdomtours.net/upload/file/63978167295.pdfIn PDF document text
    • http://hajnysport.cz/FCK_userfiles/file/600151809.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ec6925253---bunizinetumadopipo.pdfIn PDF document text
    • http://polesprogettazioni.com/userfiles/files/mipet.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/6a6mhshc7po1cmrk970b306iim/37267721152.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/31531301986.pdfIn PDF document text
    • https://meganimal.pt/site/upload/file/gituvijafoxefave.pdfIn PDF document text
    • http://geodeslaboratori.eu/userfiles/files/zinudusajiferakazikax.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/7969574278.pdfIn PDF document text
    • http://xsteelstock.com/d/files/libewosawuworaza.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/xozetes.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/43219658418.pdfIn PDF document text
    • https://rubenoferro.com/userfiles/file/xisafesaruvofitew.pdfIn PDF document text
    • http://www.rsvpcatering-ar.com/files/imagesfile/12084949166.pdfIn PDF document text
    • https://ykitraders.com/UserFiles/file/47471050224.pdfIn PDF document text
    • http://unite-chem.cn/upload/files/13585480188.pdfIn PDF document text
    • https://limsurdua.com/contents/files/83688014853.pdfIn PDF document text
    • http://tw-tms.com/uploadpic/xw/files/vejoji.pdfIn PDF document text
    • http://southerncross-ex.com/images/blog/file/54581088850.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=hack+instagram+account+without+verificationPDF 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_off0000d5d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5D2 11072 bytes
SHA-256: 9bb094641e6265abab32428b59f91b217cefc6bdf41a9c2766b9e890560d2484
font_01_sfnt_off0000ef8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF8D 18712 bytes
SHA-256: 3a4f1631c01795355e0328b6dfe270582925d4963e3fdf594e01253dfc7e934c
font_02_sfnt_off00011fd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1