Malicious PDF — malware analysis report

Static analysis result for SHA-256 c781cd59c1ef74e1…

MALICIOUS

PDF

84.9 KB Created: 2021-07-02 23:32:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: f253935bce4185ba6f911b891df4eb0e SHA-1: 179d1a1ad1a417b230a29bc516c647f7be2c070c SHA-256: c781cd59c1ef74e13fcb2f5c3b2bf600c8cddec6036edae441ce547df25b977e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to compromised WordPress upload directories and other disposable hosting sites. The embedded URLs, such as 'https://cructi.ru/uplcv?utm_term=intermittent+fasting+ldl', are likely used for phishing or to download further malicious payloads. No scripts were extracted, but the PDF structure itself is exploited for malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://cructi.ru/uplcv?utm_term=intermittent+fasting+ldl PDF link annotation
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/cd8e8b3008fff47b130a6621ffba9cf2/64718058911.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/icdtkmt45k5fhqqjrp7u17gtll/faderaguvedadu.pdfIn PDF document text
    • https://global-brand.net/userfiles/files/9197246860.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16098f00cdc3c8---82760867815.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/9658460107eaf6172fb8a1b039d3aee4/43175096092.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a8eece4b643---70064317663.pdfIn PDF document text
    • http://stpatricksreunion.com/clients/84553/File/4733526514.pdfIn PDF document text
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/1b4dfdf6182d3716d30cefe3ff6c925a/50655311362.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/d8d3b9a08d6f77032c57c851c59d5fe8/suberoneravujufup.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083e5814c34c---67891825088.pdfIn PDF document text
    • https://organicfertilizerproduction.com/d/files/bedasopen.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ba163d46a10---40536532817.pdfIn PDF document text
    • http://allseasonsart.com/uploads/fck_uploads/file/sevizurokajovavedudezu.pdfIn PDF document text
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/823ff087bffd5a043bdd0928052049e0/lojurosovasodiguzafo.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/0b930dfc89b0d1ff53c28dcb5d9802e3/benubamerukobuzimemutufaz.pdfIn PDF document text
    • http://ctyrkolky-gamax.cz/data/dokumenty/92661399343.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608f29dac23c9---gisosevepunune.pdfIn PDF document text
    • http://capri.lt/userfiles/files/73448251217.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/6c9767a31bf76d0909e41e19482d6c5a/xirimuvo.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/aa2dfc347388cddca5579ca2c7ba8cbf/89876148007.pdfIn PDF document text
    • https://eltonltd.ru/sites/default/files/uploads/fuzaxaturuximorepa.pdfIn PDF document text
    • http://www.contectrade.hu/fckfiles/file/fokadebilizopaj.pdfIn PDF document text
    • http://okulsanmalatya.com/imgup/file/14692985010.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/300635434803.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_off0000ea68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA68 10528 bytes
SHA-256: f25262dbefbeec361cb2125cb66ef368d503428026904163baa1ae4ad4c90be5
font_01_sfnt_off00010215.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10215 16596 bytes
SHA-256: bf7a7dc190696022df39ba1a9c619f073eed8ba3bde79847b5288482e1d5424a
font_02_sfnt_off00012cd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CD6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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