Malicious PDF — malware analysis report

Static analysis result for SHA-256 53acb0417502d3b2…

MALICIOUS

PDF

82.6 KB Created: 2021-09-16 17:31:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: b436040e624686d2e44f6ea0367609a6 SHA-1: 45abe6ca5a01456fec14dc7e31a7256292567a7a SHA-256: 53acb0417502d3b27b457cf303ce81a00b79d3f76ecf5b7424b37d59e5ef007d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically identified as a phishing trojan. It contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, indicating a phishing or malware distribution attempt. The document body is heavily obfuscated, but the presence of external URIs and the link farm heuristic strongly suggest a malicious intent to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://laborke.ru/uplcv?utm_term=videoder+download+apk+android+2020 PDF link annotation
    • http://metall-press.ru/files/87842780818.pdfIn PDF document text
    • http://2016.letnifestiwal.pl/ckfinder/userfiles/files/fanikufemarerixivaxo.pdfIn PDF document text
    • https://sahyadrisevasanstha.in/userfiles/file/87692313709.pdfIn PDF document text
    • http://myappartement.de/web/editor/files/18373643483.pdfIn PDF document text
    • https://onlinendttraining.net/files/tuluno.pdfIn PDF document text
    • https://it-remarketing.pl/app/webroot/media/files/zawilipelikekamox.pdfIn PDF document text
    • http://zgkimsteszew.pl/img/upload/files/poxiditupija.pdfIn PDF document text
    • http://gesht.ru/admin/ckfinder/userfiles/files/tubatosapixikuzusi.pdfIn PDF document text
    • https://speedwayinfo.hu/uploads/file/99888367573.pdfIn PDF document text
    • http://sunil.kr/uploadfile/fckeditor/file/kapisenoliletidumomuker.pdfIn PDF document text
    • http://axi-hohenstein.de/userfiles/file/57437100091.pdfIn PDF document text
    • http://rc-saty.cz/gais/image/file/33176773547.pdfIn PDF document text
    • http://tydafa.com/dafa/uploadfiles/20210905185556.pdfIn PDF document text
    • https://pierreseche.fr/userfiles/file/39188945791.pdfIn PDF document text
    • https://tckontrola.hr/files/menibogatova.pdfIn PDF document text
    • https://www.esicm-old.org/admin/lib/ckfinder/userfiles/files/jopubuduwutofiwamun.pdfIn PDF document text
    • http://swiftnb.com/ckfinder/userfiles/files/79351918576.pdfIn PDF document text
    • http://studioingegneriavaragnolo.com/userfiles/files/33963645432.pdfIn PDF document text
    • https://basisangka.com/contents/files/36651637107.pdfIn PDF document text
    • https://tjpapigroup3.com/contents/files/12950754431.pdfIn PDF document text
    • https://prestinieurope.com/userfiles/files/zuneja.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16132498e8ec6a---17478341517.pdfIn PDF document text
    • https://www.educazionesessuale-scuola.ch/ck/ckfinder/userfiles/files/xuwafujovowidijafot.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16138f654d27a9---81866895572.pdfIn PDF document text
    • 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_off0000df6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF6B 10508 bytes
SHA-256: 78bac2a014f889b944cb2b79e5b80c348db25f30b27441c08ddfb052838c6afe
font_01_sfnt_off0000f76b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF76B 17608 bytes
SHA-256: eafb8238ce52c41a487899456936363a1b4909c68bdb906b24efb77d54cf5884
font_02_sfnt_off0001248f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1248F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1