Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8c4919cbb830096…

MALICIOUS

PDF

75.6 KB Created: 2021-09-19 23:48:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 55838df77e3e162f0d4f1c4cf2c41e7e SHA-1: 54e2704142b6ed790144411b9b4b0b174b43d4cc SHA-256: c8c4919cbb83009608803ca3d4f6dd505c537846a9aceb62f1375f512110be26
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as containing a link farm and being a potential phishing or malicious document. The embedded URLs, particularly those hosted on compromised CMS uploads and disposable domains, suggest an attempt to lure users to external sites. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://crysiq.ru/uplcv?utm_term=best+free+cricket+games+for+android PDF link annotation
    • http://4998horo.gmmwireless.com/contents/files/metarinegixumolazajon.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/m08205ndbfipm8p22i89h0vt4a/jasog.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/lapugepegaj.pdfIn PDF document text
    • http://scoutpate.com/userfiles/file/migesoboguputodalofarunop.pdfIn PDF document text
    • http://dongzzang.com/userfiles/file///jadopel.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/14217141649.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/92abac28c0c8aa7009381c100df9f3ff/21736654507.pdfIn PDF document text
    • https://sakesushimn.com/userfiles/files/risulesujajoxutipa.pdfIn PDF document text
    • http://www.itidharamshala.in/images/uploads/files/72258498435.pdfIn PDF document text
    • http://hutbephottaihaiphong24h.com/upload/files/76962899455.pdfIn PDF document text
    • http://studiolorenzoni.eu/userfiles/files/lugavan.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/860bd55580bde8529aad89d93d9b94c9/gikitifixoxuxa.pdfIn PDF document text
    • http://offerseir.com/basefile/offerseircom/files/94977324007.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/jexuge.pdfIn PDF document text
    • http://thsport.dk/ckfinder/userfiles/files/vojugozejabovaxagepep.pdfIn PDF document text
    • https://www.zolmedis.lt/ckfinder/userfiles/files/29720788566.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/58184856165.pdfIn PDF document text
    • https://xebecdesign.com/xebec/userfiles/file/95826843101.pdfIn PDF document text
    • http://josephfellerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/88220567542.pdfIn PDF document text
    • https://vietucmould.com/img-vietuc/files/kanefigufag.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/99628170991.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/23a221475fcc8883fb2a4801b8dafbf4/jewusine.pdfIn PDF document text
    • https://red-adlay.com/upload/files/18766706465.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132a9c189bdb---bunuvabawevizarufezofes.pdfIn PDF document text
    • http://generoussecurity.com/uploads/sunobunuvokaji.pdfIn PDF document text
    • http://edwindijk.nl/home/edijk/domains/edwindijk.nl/public_html/uploads/file/93417566242.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_off0000c538.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC538 10916 bytes
SHA-256: 028b78d7282dff66552f2199df5c05dc63b313f72e9b925b2f3f3d9a2d0c458e
font_01_sfnt_off0000de56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE56 16484 bytes
SHA-256: 63862ff92aaf4fbe3854b931b49ffb40d9871e7b67fdc998ca4fba3ee24f6b2a
font_02_sfnt_off00010832.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10832 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1