Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c8e4815d62c41b7…

MALICIOUS

PDF

76.7 KB Created: 2021-09-08 07:49:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 79207743dd1d1b79f21c43941bf599de SHA-1: f59f87fed982ccb10334cf85206ca44d075bc68f SHA-256: 8c8e4815d62c41b7ce15e9ab0685170f1131d4a68dfcd0cd3c2673bc0d30a58e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised websites or disposable hosting. The primary purpose appears to be directing users to external malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=organs+of+speech+diagram+pdf PDF link annotation
    • http://iwilldoit.ru/uploads/files/files/76670444808.pdfIn PDF document text
    • https://aadharshilaschool.org/userfiles/file/95758806643.pdfIn PDF document text
    • http://dynamic1984.com/user_file/file/403487994.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/8c69f0ac209233d51b2cdeae5d0c8740/1051895597.pdfIn PDF document text
    • http://www.dean-cpa.com/files/adminpic/file/viralipubuzurukepubajo.pdfIn PDF document text
    • http://hncastlecable.com/d/files/tasefasimisivapedixuzi.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/gizakutekasewaretugekel.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16096a55ef2e02---80037923064.pdfIn PDF document text
    • http://fitviewer.biz/files/file/jobukesituforimadaluvaroj.pdfIn PDF document text
    • http://biatlonbreza.sk/editorfiles/files/50745233589.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/qrehb1n21meft7ueafo800o9j3/xaruxepiripa.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/81424512125.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/789b986c8a4a708b875e59fe47673094/janutofononafako.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/1659837601.pdfIn PDF document text
    • https://aedwea.com/upload/foto/zukusedijelovalo.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/98035a182cd1e883ef7c10f81333bce2/vinedotivurepizurigidi.pdfIn PDF document text
    • http://solmoda.it/userfiles/files/93241565605.pdfIn PDF document text
    • http://energo-winstal.pl/userfiles/file/pogimuza.pdfIn PDF document text
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/a6ea83ee806deaa4ab18326ba83c491d/98351837677.pdfIn PDF document text
    • http://kuryakyn.ru/userfiles/file/79413107612.pdfIn PDF document text
    • http://bumsnab.ru/uploads/files/11484210138.pdfIn PDF document text
    • http://fondationmonetoile.org/clients/0/0e/0ecfe6182781ff486fe5156d2e85c11d/File/podibomigu.pdfIn PDF document text
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a56c8fe0665---81623199632.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_off0000ca18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA18 10948 bytes
SHA-256: b971884b5e6a0c96413299f388741b283adc0e58fd0eebc136aed73ae832fed2
font_01_sfnt_off0000e30f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE30F 16664 bytes
SHA-256: 93706d9b593a99f7286016aa0dbce6aa5213e1d5e0ecf7ad1038f8ed40157a8d
font_02_sfnt_off00010d85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1