Malicious PDF — malware analysis report

Static analysis result for SHA-256 11a87cf074778853…

MALICIOUS

PDF

85.8 KB Created: 2021-08-17 17:33:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ac44b8a1debdc6a078a96a88a0df08f1 SHA-1: 651493821c90c18a278946faaab081123a3fa938 SHA-256: 11a87cf074778853df49c78252a7e84cd821f9a954ee640c65bc98b782fb5514
156 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, but the presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics confirms the link farm nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f98cbc6097---dixolelos.pdf In PDF document text
    • http://medical-1669.com/userfiles/files/tutekuzedasesikatamiku.pdfIn PDF document text
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/ec9e95a8d05371f76ac0bc35b1072d76/wewusasowogazasoderes.pdfIn PDF document text
    • http://wm-meyer.de/meyer/admin/editor/ckfinder/userfiles/files/82103667201.pdfIn PDF document text
    • https://b2b-intelligence.it/uploads/file/davipujarabolunipeju.pdfIn PDF document text
    • http://1960whs.com/clients/7/73/73384dfd0d582a2861cf356c55c3c578/File/96399920034.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16097befad01fb---xosotolazufavogoda.pdfIn PDF document text
    • http://czdashan.cn/uploadfile/file/2021051512335473499.pdfIn PDF document text
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/76dvd8ecm4oe93e3t7lm44gs98/78442652263.pdfIn PDF document text
    • https://luminex.pl/upload/file/jetaxilikezika.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607ded7b47b61---sibolekimuza.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a75d183cad---40065530759.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/tuzapaduniwizatupurijegaz.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aaf38eac836---bilenararojazatatafum.pdfIn PDF document text
    • https://flyags.com/editorResources/file///numulemufelevutemevan.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160823e0e094f7---febotutokanixasewukodofe.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b01c44dc27f---66856307483.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ab7b531ea6b---54329435511.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/93e73032bce8fd24cedbc7994d5b19e5/88862516866.pdfIn PDF document text
    • https://francois-daulte.com/ckfinder/userfiles/files/34744157418.pdfIn PDF document text
    • https://basundharamart.com/userfiles/file/13069188371.pdfIn PDF document text
    • http://abcbyspu.com/ckfinder/images_store/files/gewomosujixejero.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/82425219120.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/84089331141a92bc8f42fa95556a046c/72176583096.pdfIn PDF document text
    • http://jcon-aps.dk/userfiles/file/38470555050.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=pearson+physics+11+textbook+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_off0000eb1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001032f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1032F 17088 bytes
SHA-256: e058b6942a7210f271d7b5ab0c51e25301a072875d12710d49a0b1adadd8c5cf
font_02_sfnt_off00012fb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FB1 11172 bytes
SHA-256: 9aa8dfd27503ae57c1f9a672cb1f37800a6384a8600745d1a2d0eb94b4c8016c