Malicious PDF — malware analysis report

Static analysis result for SHA-256 878f6e583af5d381…

MALICIOUS

PDF

88.5 KB Created: 2021-08-22 04:35:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f97094d3ac035270d391d77808e69513 SHA-1: 93b438c5250d2afbf2ababf6d1f6a4c6335b0180 SHA-256: 878f6e583af5d3811603a15f728d1e4e2d55eb6d7a7df26c21fc32062a737d12
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, with multiple distinct hosts and URLs. While no scripts were directly extracted, the nature of the link farm suggests a phishing or malware distribution attempt, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c2a1d31038---91733840885.pdf In PDF document text
    • https://diedacorporation.net/freesiafiles/file/2489111249.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/mdb2n1ik34fb5pcvah20jt94f3/vifun.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/1420936c9cae340d3e5c773ea5e8b689/kilidepaniguj.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/68298594641.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c7363eb31f8---40252272501.pdfIn PDF document text
    • https://podereilmontaleo.it/writable/public/userfiles/file/leligotuvewovoxigadodu.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a8a81b1ee21---rapevixanoxirolufawovan.pdfIn PDF document text
    • https://detskeihriska.eu/ckfinder/userfiles/files/54658309837.pdfIn PDF document text
    • http://flightshop.jp/images/blog//file/madafabonafigurajifuteg.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba7a257aa24---41152698242.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fc8aaa525b---tajavusowib.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/4l68apfafan8kglciohjo53al4/84964993048.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/8fd36d33ab6d9b680d18c69f82cf358e/ruloxixetiruniviwekud.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160915f1019c9b---mebafijebo.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1611b8b9db1466---safusep.pdfIn PDF document text
    • https://coatielectronica.com/files/93102520193.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/gefaxemigepetogu.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/95qrtanukisb982fqik516urpc/65646693089.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/witofari.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=problemas+de+equilibrio+quimico+resueltos+pdfPDF 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_off0000f494.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF494 11064 bytes
SHA-256: f20dff2b16428c0bbbb7e1f97c71a91a8585742c8d61da8deed55bb922b63228
font_01_sfnt_off00010de6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DE6 17668 bytes
SHA-256: 4645739c9d178b9986a3ee1c557f75e23d80878f155b0d260b0e0d05682b1dcf
font_02_sfnt_off00013afa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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