Malicious PDF — malware analysis report

Static analysis result for SHA-256 428635fd1255e30b…

MALICIOUS

PDF

71.2 KB Created: 2021-09-04 01:17:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 157dd6dbf80b4f08f397f66bf1894518 SHA-1: 4fe0cf1953e3cb9b7944f6324e3c373e8a44d3aa SHA-256: 428635fd1255e30b9816986f33c7779236f68a1c90034085968392061dcac43f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://laborke.ru/uplcv?utm_term=gestational+diabetes+blood+sugar+log+pdf PDF link annotation
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/3bec62a56567484dcf4274bb63eb4c65/27771198577.pdfIn PDF document text
    • http://analogsys.com/uploaded/file/206767717608b0cb3bbff8.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd6fbbdf54---tozab.pdfIn PDF document text
    • http://balie.overeembv-profielen.nl/upload/files/lipizakowitovuk.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/38239e37e1cbfa491d5896d9bc228917/68606585655.pdfIn PDF document text
    • https://www.rowtheerne.com/wp-content/plugins/super-forms/uploads/php/files/c58060e6f8dcee182c54c65002037ff2/galagirusijabivixibokolad.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070d91613df6---wafofobumidofitokixok.pdfIn PDF document text
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/6072636433e10801792facb9e496c628/82229769150.pdfIn PDF document text
    • http://graviroz.hu/ckfinder/userfiles/files/34115369171.pdfIn PDF document text
    • http://archinfo.ru/uploads/file/967962893.pdfIn PDF document text
    • http://dzbnf.com/upload/file///makod.pdfIn PDF document text
    • https://andrejc.si/files/file/95460314417.pdfIn PDF document text
    • http://bayernglobal.de/userVZ//file/52994303564.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080d18c26cf9---lewutuwipilometik.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/misatiradulusol.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/63754901900.pdfIn PDF document text
    • http://epmresearch.org/userfiles/files/fisojizixer.pdfIn PDF document text
    • http://ridendo.cz/files/file/zuloz.pdfIn PDF document text
    • https://airflow-skateboards.com/userfiles/files/38676753930.pdfIn PDF document text
    • https://anukulagrotech.com/userfiles/file/zigobigu.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/530bd6e2132b9ce15c6701d4f9f9c2e7/mirumanokuvolujajuf.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_off0000b501.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB501 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD13 16268 bytes
SHA-256: 0e57546c9cfc9b9523c47a524ad12be61de9467142ea377819d4d7b3def9747b
font_02_sfnt_off0000f665.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF665 10952 bytes
SHA-256: 743ec38fcf078065d19f204169a3fa2fce26fa6fa11c46e9618177be9f676514