Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f531566065314b8…

MALICIOUS

PDF

81.6 KB Created: 2021-08-29 00:49:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 47b49b0e71e5666f0ee00d80254d355a SHA-1: 589eaed32ea17f3686edace66458c516f2139026 SHA-256: 4f531566065314b8c85fbd8083c36ca26d1cd8abac80c6dbf73e09508bf9ce13
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple URLs pointing to compromised WordPress sites, indicating an attempt to deliver a malicious payload. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely responsible for initiating the download or execution of a secondary stage, exploiting vulnerabilities within the PDF reader.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://nitexprofi.cz/userfiles/file/42267909220.pdf In PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aab2bba4cfb---69795630638.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16102dedfdceb1---lofali.pdfIn PDF document text
    • http://www.ortodonciaelisafarache.com/ckfinder/userfiles/files/77709007479.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9ca35660c---zakaminu.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c2256448f---bitigosolodikixil.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160860208bc455---8803570533.pdfIn PDF document text
    • http://mackyz7automotive.com/js/upload/files/bovoretevuwalu.pdfIn PDF document text
    • http://allseasonsart.com/uploads/fck_uploads/file/kipimupofo.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/zefufininufisusom.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/64594582291.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/96316279202.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/vopomutoniragerijone.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021082208483473499.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/vudugenofujevaviz.pdfIn PDF document text
    • http://www.cpnatacao.pt/backoffice/ckfinder/userfiles/files/77065365089.pdfIn PDF document text
    • https://isabellepieman.com/userfiles/file/mikevoguvebikapidalem.pdfIn PDF document text
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/5a380bb982e73898ba6f76db9b44c1a1/titodakosasajaralut.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/guxefab.pdfIn PDF document text
    • http://group-anons.ru/userfiles/files/69506555117.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095117444bda---zenabinijowufefub.pdfIn PDF document text
    • http://sanarina.de/ckfinder/userfiles/files/lugivojupepofag.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1606f097f2cbba---gozogenudewebapo.pdfIn PDF document text
    • http://liyangah.com/Upload/file/kuwutojaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=student+loan+amortization+excelPDF 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_off0000d991.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD991 17900 bytes
SHA-256: ec409fcf792c7514074310f8e68d1bfd35563ae783fcce4cdd4c4dd84cce15d6
font_01_sfnt_off000107c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107C1 10700 bytes
SHA-256: d86aafbc0286ef4af8d96574e6d6b08a4e3fae94ebc67a55800b91ec79efaa9e
font_02_sfnt_off0001205c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1205C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1