Malicious PDF — malware analysis report

Static analysis result for SHA-256 c37efb886aefa48f…

MALICIOUS

PDF

79.3 KB Created: 2021-09-06 22:31:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d24d83c5bb07ffdf67e49f53f9272ebd SHA-1: 7b760101b97dcc493dba0a341b690b0effb686a3 SHA-256: c37efb886aefa48f38a1f6a14d7a2c568f2ac82f1d232d6ec5ad5dd9f9a83c2c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classification and ClamAV detection. It contains numerous external URIs and links to compromised WordPress sites, suggesting a phishing or malware distribution campaign. The presence of embedded URLs and the nature of the heuristics indicate that the PDF likely attempts to redirect users to malicious external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://inwebjor.ru/uplcv?utm_term=adding+and+subtracting+rational+numbers+free+worksheets PDF link annotation
    • http://mirsistem.com/depo/sayfaresim/file/93113623805.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e2bcf08987f---guvutuwefebiwofip.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/86e080eb549901e15fb68cfdb9242c03/jajenigepekaziwemexol.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/342368f72ecae63b1816067f59f417f9/magosakedawaro.pdfIn PDF document text
    • http://musicupclose.com/clients/f/f7/f7c291dfb329fbc33054893077acf627/File/15814729249.pdfIn PDF document text
    • https://sfeerweter.nl/userfiles/files/3211482318.pdfIn PDF document text
    • http://volkshilfe-vlbg.at/images/content/files/puxevegisijifekaxamumi.pdfIn PDF document text
    • https://rheinfurth.de/userfiles/file/27597576999.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9216600cec---2756310533.pdfIn PDF document text
    • http://mulherinscampground.com/clients/879992/File/wemafaroxovidapepoluz.pdfIn PDF document text
    • https://rdsdealers.com/ckfinder/userfiles/files/86333489896.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608513be09f7c---26272241009.pdfIn PDF document text
    • https://classykitchen.pl/web/uploads/files/31494660453.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/jii44e7va88cmqsmv0mod18ttt/79687605437.pdfIn PDF document text
    • http://ttccid.com/userfiles/files/dufegaleme.pdfIn PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/88943732375.pdfIn PDF document text
    • https://fullhousetourism.com/UploadFiles/file/20210630020834119.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/60342265568.pdfIn PDF document text
    • http://ingenermarket.ru/userfiles/8776257458.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/516780b9518f5e931844de9354e2bfca/gilavawuxitikumodimuv.pdfIn PDF document text
    • http://hasanmasat.com/ckfinder/userfiles/files/47073378368.pdfIn PDF document text
    • http://market-oborudovanie.ru/upload/file/lidemuniman.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/1ha1eilt372rk691gbi685op66/4656764764.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/icfis1f1c7qnfsr4i8v6gvgaug/bunogufutelukenajif.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d644c4c329a---sejolusegofe.pdfIn PDF document text
    • https://bushregenerators.biz/userfiles/files/bunefakewexosato.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_off0000cdc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDC1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e5d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5D3 17832 bytes
SHA-256: a71c106bc6c7f53b49ca7ad7aa57bf8dd5b17013ccbbe7fb6595bcbcf883b84f
font_02_sfnt_off00011471.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11471 11324 bytes
SHA-256: 93103501384bc5f31a96ee592985087294b776288fc82e0b3e194b62fec65ef0