Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91ddfaf78b09e60…

MALICIOUS

PDF

68.8 KB Created: 2021-09-29 01:18:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c829b64b52825cedc9596e2023b57048 SHA-1: 4d3dcd63d7237a363c14ee2693cf84039be70c2b SHA-256: c91ddfaf78b09e60ec574bd2fad4c656332ea184d28676517656af6752c4cf99
156 Risk Score

Malware Insights

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

The PDF contains a link farm, with many URLs pointing to various domains, some of which are hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO poisoning or directing users to phishing sites. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://newcar-rental.com/uploads/files/202109251520006046.pdf In PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/16136f72c1ed43---tonupezutozip.pdfIn PDF document text
    • http://halanmilk.com/upload/files/26927626340.pdfIn PDF document text
    • http://domoticasociale.it/immaginiNewsletter/file/598499857.pdfIn PDF document text
    • http://iberia-ex.com/images/blog/file/89283741956.pdfIn PDF document text
    • https://heyratacademy.ir/file/wanuladexok.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea945bd1ec---19905564645.pdfIn PDF document text
    • http://www.farmaciapenil.es/userfiles/files/fologubisidexat.pdfIn PDF document text
    • https://tktravelkorea.com/FileData/ckfinder/files/20210923_C08F4B710B959AF3.pdfIn PDF document text
    • https://latework.cz/soubory/jikofezodowetuxot.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/161390fb530061---labeb.pdfIn PDF document text
    • http://weilandensemble.nl/ckfinder/userfiles/files/midanilekefoda.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad2e38f016---61654072787.pdfIn PDF document text
    • https://pakianco.ir/data/image/uploads/news/files/35712797880.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/03dc072edffc06c001898cff996dab39/47948183270.pdfIn PDF document text
    • http://vektorma.ru/uploads/assets/file/fevef.pdfIn PDF document text
    • https://krafteco.ru/uploads/files/josoparikowelijokijisefo.pdfIn PDF document text
    • http://artechq8.com/beta/uploads/files/sazod.pdfIn PDF document text
    • http://antropolog.ru/userfiles/file/38256514769.pdfIn PDF document text
    • http://bigyikesmedia.com/home/xtremweb/public_html/consultinstitute/web/upload/files/zemosezuf.pdfIn PDF document text
    • https://hearing-outlet.com/uploads/files/202109172313319824.pdfIn PDF document text
    • http://myshiou.com/uploads/files/202109090106046023.pdfIn PDF document text
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/81781786100.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/q1k5biaia3grg6uq22moi5fk5u/fafikonemisipakufudiniz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=monster+saga+pokemon+game+downloadPDF 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_off0000b0f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c906.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC906 14356 bytes
SHA-256: 30af0a3fc283836e6f5a9e8d22f4344ea7ffcc5a4c1fed2e67b42a64482c9d4c
font_02_sfnt_off0000ed05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED05 10812 bytes
SHA-256: b9d1a65145e8ffddadd161a9fe86728d7b4393788911030f44cab7283c4ce82e