Malicious PDF — malware analysis report

Static analysis result for SHA-256 73982b2010b6c50c…

MALICIOUS

PDF

78.7 KB Created: 2021-09-15 12:31:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a91d4a1e59607d8083a6ee73f5612bba SHA-1: bff76e5ab2bd613bb5c524fba0d4cb1c91caa3f6 SHA-256: 73982b2010b6c50c32101d1f1c88d4b021234d1313608f0ae666477c6c8dd2a8
142 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple external URIs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of a 'download button' lure further supports this, suggesting the embedded JavaScript is used to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://digifast.cz/userfiles/26545926799.pdf In PDF document text
    • http://dentherapia.hu/files/file/gidobot.pdfIn PDF document text
    • http://purepassion.pl/userfiles/file/desetiselumumepilivojon.pdfIn PDF document text
    • http://skoleniridicubrno.cz/ckfinder/userfiles/files/tulewid.pdfIn PDF document text
    • http://udokutscher.de/gfx/userfiles/files/dezagajodidozavudisedij.pdfIn PDF document text
    • https://bauarch.bg/files/75232166610.pdfIn PDF document text
    • https://ehlibeytalimleri.com/resimler/files/xagijolidulekojimaxejok.pdfIn PDF document text
    • https://kemxoithanhhang.vn/app/webroot/files/images/pages/files/wevafiviwegilizazepilif.pdfIn PDF document text
    • http://spartapr.com/images/upload/file/80952951786.pdfIn PDF document text
    • http://kreativitaet-stadlhofer.at/global/images/userfiles/file/74312699069.pdfIn PDF document text
    • https://shian-jin.com/UserFiles/files/jogepapawuninija.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/3af081c1abad84a663ba0d1268a3d01b/jojoxovebizok.pdfIn PDF document text
    • http://montazerangroup.com/uploader/file/40419125628.pdfIn PDF document text
    • http://apexnepaltravel.com/userfiles/file/14966422335.pdfIn PDF document text
    • http://kitpaisal.com/mypicture/file/1322813973.pdfIn PDF document text
    • https://akproauto.com/nbloom/fckuploads/file/fujowokadinizadejuli.pdfIn PDF document text
    • http://victoryelectricalsupply.com/ckfinder/userfiles/files/motodejerodadaj.pdfIn PDF document text
    • http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/wekovajazobu.pdfIn PDF document text
    • https://univerosg.com/ckfinder/userfiles/files/rasusesasamukuvonuvuladu.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16140d29059543---rewifuje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=watch+online+web+series+free+appPDF 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_off0000cf0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF0F 17560 bytes
SHA-256: a3fa87f4958b239b4864b823542e8c9a25c2648fd5812dfd3096444fc5a69f8e
font_01_sfnt_off0000fccb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCCB 10796 bytes
SHA-256: 3a67c82771e9bd9f2ff958ce243a703de383da77bd15480cc31c1e512f5bdfef
font_02_sfnt_off00011575.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11575 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1