Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c1ee9c246293393…

MALICIOUS

PDF

76.6 KB Created: 2021-09-18 05:18:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: eb11ef8e039f047525cafa9987a96dc0 SHA-1: 0da0f4881d1f42f1ce6b815de31e55124062f178 SHA-256: 1c1ee9c246293393217bc94d35132c84ed4ebcf0e9a827ce61251a207e3edbdc
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of external URI heuristics further supports its malicious intent. While no scripts were explicitly extracted, the structure and embedded links suggest a phishing or redirection attempt, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 5

  • 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://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1613a89481d46b---1993894152.pdf In PDF document text
    • http://classtool.info/upload/files/94536746516.pdfIn PDF document text
    • http://svarovani-tig.cz/userfiles/file/felifelobimofisumewojufil.pdfIn PDF document text
    • https://www.idd.no/ckfinder/userfiles/files/28640856359.pdfIn PDF document text
    • http://ricettebiagi.it/uploads/assets/file/42763132099.pdfIn PDF document text
    • https://mepho.hu/ckfinder/userfiles/files/76971959519.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/16139ebb433656---3728539336.pdfIn PDF document text
    • http://zdravi-kromeriz.cz/files/file/vakizozolajarutatolize.pdfIn PDF document text
    • http://ychnjl.net/userfiles/files/98580856499.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16142081d6756e---gesoluwoxodonijona.pdfIn PDF document text
    • http://lukinserv.hu/file/14411090881.pdfIn PDF document text
    • http://dominant.name/userfiles/file/pupigepeg.pdfIn PDF document text
    • https://manage3.realtourvision.com/rtv/ckfinder/userfiles/images/files/vadiloba.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/lalopafowapo.pdfIn PDF document text
    • http://klenderbio.com/upload/files/69413592582.pdfIn PDF document text
    • http://linkipt.com/_UploadEditor/files/69428601054.pdfIn PDF document text
    • https://patriciogaete.com/upload/file/kixipo.pdfIn PDF document text
    • http://hotelborgodeipoeti.com/userfiles/files/40524140399.pdfIn PDF document text
    • http://zaiger.ru/img/file/vosiratinafibepaju.pdfIn PDF document text
    • https://mackbeks.com/files/file/85080562515.pdfIn PDF document text
    • http://omatsuri.kr/data/userfiles/files/77101887526.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1613f497fb5c23---58388728717.pdfIn PDF document text
    • http://stefani.cz/fck/file/23367275752.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=dr+parking+4+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_off0000ca8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA8D 16252 bytes
SHA-256: 21b624da7afaa3be318656dfd2db3c87aeed271e7aae37977f346ee1d7d50e45
font_01_sfnt_off0000f4af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4AF 10724 bytes
SHA-256: 5810093d262623cacf0c95ae651cd3dedb7bfa84a5e539205dfd386f0838ed47
font_02_sfnt_off00010d13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1