Malicious PDF — malware analysis report

Static analysis result for SHA-256 837c2be4b7e513e8…

MALICIOUS

PDF

94.8 KB Created: 2021-07-07 11:21:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-18
MD5: b37bfa231efb2682d9e58445e5acad87 SHA-1: 6ff7ec460c666382a182c88631a45833e9821214 SHA-256: 837c2be4b7e513e83d69cf528de45652a6a6728edac342dff9b7df6bf0f5a8e2
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to websites hosted on compromised CMS platforms, identified as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple compromised upload links suggests a coordinated effort to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607db63a0cfb9---widakar.pdf In PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/24jisa79jrstq78prp3e7lkakp/setafupafekogo.pdfIn PDF document text
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/jsnrkm0v55agmr6rpu3u2q335r/73318526715.pdfIn PDF document text
    • http://studiomuraca.eu/userfiles/files/42922871974.pdfIn PDF document text
    • http://aps-mes.com/files/file/dovuridon.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/panafizebexedaxogeliwej.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/96912419272.pdfIn PDF document text
    • http://geodeslaboratori.eu/userfiles/files/24234280703.pdfIn PDF document text
    • http://www.golfusa.be/userfiles/files/xobuwisewokot.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/68b11af0f0875446886e07862704da8d/89411876258.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16096ded09eb29---patuburusosiwikoliranud.pdfIn PDF document text
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/704a6641030c1504aa24ed505a753715/zuzakoji.pdfIn PDF document text
    • http://iphysiology.ru/upload/nizotefuxidasiwu.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/ce4928cbe2b11f749e0040ffd196ecec/vuboravovedoj.pdfIn PDF document text
    • https://cr2tek.com/userfiles/Proj_Name//files/loromimozagawu.pdfIn PDF document text
    • http://alexandraharris.com/clients/36054/File/13069584599.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/40497480470.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160870b447befe---dibumikuxemonegibosubobo.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c93cd728b---42876512584.pdfIn PDF document text
    • http://edgecs.net/documents/20961276873.pdfIn PDF document text
    • https://minutesnap.com/wp-content/plugins/super-forms/uploads/php/files/39eeea8199f4ebb15509084834c0cd13/50186063130.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b91c0327977---modulidebaguninipokugaze.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/dawonafikepupi.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160ce05a58c7a0---sizuxewezuviwusog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=acer+aspire+8920g+service+manualPDF 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_off00010b39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B39 17580 bytes
SHA-256: b5000c41ce247a8191643665c6f6735a6bf505e86f845bfb2eff4c9b1a8e27d2
font_01_sfnt_off00013974.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13974 11264 bytes
SHA-256: daa6583bed3d984cf4d2a5c87929402f3ccd933b79cc3e07848a7dc4ff775f2f
font_02_sfnt_off000153ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x153EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1