Malicious PDF — malware analysis report

Static analysis result for SHA-256 5716d1718ada6de8…

MALICIOUS

PDF

79.1 KB Created: 2021-06-21 17:31:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 7c64e0d4043e9b060dc31be81ad246a8 SHA-1: 6cbbcf1042cd562056ab3e17cf575cf41fef5507 SHA-256: 5716d1718ada6de8965c971ed45c0ebe98d0ec995e13c542fe238bd09858d758
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to multiple compromised websites, each hosting another PDF. This suggests a multi-stage attack where the initial PDF serves as a lure to redirect users to further malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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://amirep.com/wp-content/plugins/super-forms/uploads/php/files/adbd56ff6f5e8b8b0e8d8eebe69f5663/85846256181.pdf In PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a086b4598e4---3843271351.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072230b68e90---xumogixasozututitebi.pdfIn PDF document text
    • https://songhong-thudo.com/img/files/85943153768.pdfIn PDF document text
    • http://www.ximangsongthao.com.vn/app/webroot/uploads/files/48435560685.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609c883f064c3---memevebiwi.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/qij4ljrjfci9o0c85vatd10mi4/wanifazuxas.pdfIn PDF document text
    • http://interno-kazan.ru/upload/files/83622720722.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1609f6714c007e---tuluzevodobunawasetad.pdfIn PDF document text
    • http://ownlines.com/upfiles/file/25697597944.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4175eb3ea8---pigafavalelelona.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/11942162121.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ac64ef36067---sawejosidibuwopevux.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609dbcb4e541a---xugovepobitu.pdfIn PDF document text
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/339f2e035ad2f26d5e2ba9ec95034da2/kulatilumikesaloro.pdfIn PDF document text
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/38641993184.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=units+of+molar+absorptivity+in+beer%2527s+law+equationPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f025.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF025 5592 bytes
SHA-256: fbb706c8e6b60f646d3a2951e55470a905235231a97d1a160195a0356d61e5a8
font_01_sfnt_off00010336.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10336 12352 bytes
SHA-256: f4ff18818602c0f07b0327e8ad2dc60a5afc0482e300e7fa2124726ea304fabd