Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cbcaabd5c1cc2d6…

MALICIOUS

PDF

74.8 KB Created: 2021-09-21 09:20:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ad95e2bfa5e94593467e966639376dcf SHA-1: af241c8f0b171acece60244ec7c20bd192862f33 SHA-256: 1cbcaabd5c1cc2d62b22c3c4b4a0dcee78f96d572c16eae5f52b19012c9ee83d
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to PDF files on various domains, indicating a link farm. Several heuristics flag this behavior as suspicious, including 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9903

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://shturnev.com/files/foFKED/file/bidunebevaj.pdf In PDF document text
    • http://morard-mcf.fr/data/Files/32212862570.pdfIn PDF document text
    • http://ecohouse-lab.de/userfiles/file/75285522284.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dbf078b66a---44118017877.pdfIn PDF document text
    • http://ambulatorioveterinariorigolon.eu/userfiles/files/89503247531.pdfIn PDF document text
    • http://adasbruiloften.nl/userfiles/file/ruleg.pdfIn PDF document text
    • http://dotacjedlaoze.pl/userfiles/file/xodegoroti.pdfIn PDF document text
    • https://rtvpuls.com/ckfinder/userfiles/files/gilikojidetugupoguxilat.pdfIn PDF document text
    • http://hoteldanang.com/uploads/images/files/77304746808.pdfIn PDF document text
    • https://gentrilieu.vn/userfiles/file/26409728476.pdfIn PDF document text
    • http://kajo-frings.de/userfiles/file/kofinati.pdfIn PDF document text
    • http://leton.pl/userfiles/file/1294205378.pdfIn PDF document text
    • http://doradcyprawni.com/images/pliki/83219444544.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/45aefd0a2b61e4441bd75230667c69e1/46849902902.pdfIn PDF document text
    • http://trevorhannant.com/dedig.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/161476b5bea4c1---36637319881.pdfIn PDF document text
    • http://reguitti-engineering.it/userfiles/files/wofugoxedozebagewojokaz.pdfIn PDF document text
    • http://devitohomesorlando.com/userfiles/files/kuluxufaxu.pdfIn PDF document text
    • http://www.og2c.com/images/file/1743021169.pdfIn PDF document text
    • https://www.anoregmt.org.br/ckeditor/ckfinder/userfiles/files/wuzebukumupukolasiwel.pdfIn PDF document text
    • https://interstudy.net/userfiles/file/72569789796.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16136e2ce97f59---luzareputifaz.pdfIn PDF document text
    • https://marblo.marblobaths.ph/app/webroot/img/files/jagofineropoborapudagudom.pdfIn PDF document text
    • http://zamaro.cz/images/fcke_files/file/82975738720.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=faug+game+official+websitePDF 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_off0000c1d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9ED 10776 bytes
SHA-256: 1b823e3c8520060298096f876e0b56c47a3664f0c91cb63f040b9bbce1263b0c
font_02_sfnt_off0000f2da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DA 16696 bytes
SHA-256: 5c58f251d76e0f100734a7caeaf8184e7d9aadd69b19107e3fe2dfde68bc09c5