Malicious PDF — malware analysis report

Static analysis result for SHA-256 a11ef6dc16799179…

MALICIOUS

PDF

79.5 KB Created: 2021-06-25 14:17:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: f34fd778600ed7986e20d3aedb10e63a SHA-1: bc59a633b050766a93f9c4e963d080ed28bc0314 SHA-256: a11ef6dc16799179bd4233f512e86c4b188695c2691ddc2e822eb5104b7f7739
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites and other disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to host malicious content or redirect to phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://inwebjor.ru/uplcv?utm_term=the+new+colossus+by+emma+lazarus+worksheet PDF link annotation
    • https://hse.tw/upload/file/sepuzefegufi.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/21702635314.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/8n51mt8fe7ic9jvcvvo0164896/64586049133.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/40m1v2evf9o35lionkgodsg687/12594530146.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d50db85e313---devofidazefobuwuko.pdfIn PDF document text
    • https://daaeportrett.no/upload/file/lalajotowatepev.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/1rjgvm25g76i85iuiu13co0qdc/66950110440.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095eebded591---dalezanufuso.pdfIn PDF document text
    • http://tznjl.com/userfiles/files/meralusidomabazeda.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/501195dfb3d6e048408f717f22735fef/kizorikisefusuz.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/96299577862.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160bf4eed31139---xadokadimusirul.pdfIn PDF document text
    • http://stark-tools.ru/images/uploaded/32851765795.pdfIn PDF document text
    • http://global-insurance-broker.de/downloads/fisasenanenupu.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/bcbd5e01bab4c0bf3c06f7fdfbb5578a/81154344054.pdfIn PDF document text
    • https://sudhirsachdevaclasses.com/ci/userfiles/files/kemefevamufomulupage.pdfIn PDF document text
    • https://mallncart.com/userfiles/files/86981349184.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_off0000d345.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD345 17052 bytes
SHA-256: 78df32cff13cea212878f6f83e6de16a7cbd67d5ed884af58913cad4277511ed
font_01_sfnt_off0000ffb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFB9 10960 bytes
SHA-256: 67c601eb59285c96bdf917ecdadbe54bcd6374d386d2969e6291a6ba46c95196
font_02_sfnt_off00011924.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11924 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1