Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81c7f17af6a98da…

MALICIOUS

PDF

95.4 KB Created: 2021-06-27 15:52:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4c8cb49bb9104659095ed6183e9f10d4 SHA-1: 595b6aeb91abafc7fb4b07f96a2f59d518bec101 SHA-256: a81c7f17af6a98da333c321f9dcdb34c212aa84437dc15eb7064d4704c0e2fa7
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other domains, likely intended to lure users to malicious content. The presence of multiple PDF link farm heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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 http://serramentisiciliano.it/userfiles/files/43514039071.pdf In PDF document text
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/jl1u2adl3m2e22obcos8fammjv/mavokozanu.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16082fde87899f---zaviri.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/a9bbb33b34831ad507673e8576bdce3b/pabeduzubamemakudajufalib.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/vanuveropuwaborukepiju.pdfIn PDF document text
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/0586692c822dac9ce642feb5b9e0cd10/pukawawomivofoborosaribo.pdfIn PDF document text
    • http://ayurvedicclinic.org/userfiles/file/xupujig.pdfIn PDF document text
    • http://cestovni-postylka.eu/userfiles/file/79846308468.pdfIn PDF document text
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/c1c6076c9330a7e2f065413bd2404aa1/binanagiwapobuxejop.pdfIn PDF document text
    • http://www.celso.org/download/redila.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa6a2b185b---sejobevenu.pdfIn PDF document text
    • https://menlopark.com/wysiwygfiles/file/dubumisu.pdfIn PDF document text
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160829be244603---43318661191.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a27f821924b---52114870859.pdfIn PDF document text
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/fp83vj0f363ilf4fr653qrhlih/33420384400.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160848161cf8b3---bobaxiperamede.pdfIn PDF document text
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/03732a138aa6be6a2f5841aeb68f32f9/77415523329.pdfIn PDF document text
    • http://endustriyelkiralama.com/wp-content/plugins/super-forms/uploads/php/files/6f8fpq5c1r06r9vchjc5q1rld3/valofisukoso.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0bf7ce307e---tonedeve.pdfIn PDF document text
    • http://bostonmentors.com/userfiles/file/suzoxotitifozutevadadapob.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609630af0ed30---vizadawotapoki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=the+jilting+of+granny+weatherall+charactersPDF 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_off00011057.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11057 10908 bytes
SHA-256: d67c83ae9583770060fdb942f37a479115e48b8e7a09006b7ebb121101d60de2
font_01_sfnt_off00012994.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12994 17208 bytes
SHA-256: 895d2a96e52806eb4609417512bc694534a35dd3688c1769147f8bf704382c34
font_02_sfnt_off00015658.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15658 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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