Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b41cb0d5b079a3d…

MALICIOUS

PDF

73.5 KB Created: 2021-09-12 19:13:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: fbfe68cede4b351fda0a5c2a43047db1 SHA-1: 7f122ead524bb6da33862bcad48396a4ff54f1f0 SHA-256: 0b41cb0d5b079a3d81f6355486133d45594e67ec82a1bcb8e34090b84bd3eec4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. Although no scripts were explicitly extracted, the PDF structure and link farm heuristic indicate an attempt to exploit users via external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://4chan.ro/UserFiles/file/57056636998.pdf In PDF document text
    • http://studiolauramoschini.it/userfiles/files/tetes.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612f30e0d8d2d---63621373277.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/187d5ae4a0eb0d56301fee89d9916863/89444231858.pdfIn PDF document text
    • http://nitecoreromania.ro/files/file/gudem.pdfIn PDF document text
    • http://kennycojewelry.com/userfiles/files/202109/1630801700.pdfIn PDF document text
    • http://platcometals.com/images/file/rexatezozuletutev.pdfIn PDF document text
    • https://agrocare.ro/ckfinder/userfiles/files/10922819509.pdfIn PDF document text
    • http://elencostruzioni.it/userfiles/files/20479388228.pdfIn PDF document text
    • https://kokomanis.com/contents/files/34427931845.pdfIn PDF document text
    • https://colakcivi.com/userfiles/file/67192445307.pdfIn PDF document text
    • http://jl-vacuum.com/upload/files/delazeruz.pdfIn PDF document text
    • http://greece-ex.com/images/blog/file/52983934691.pdfIn PDF document text
    • https://zegaoyun.com/calisma2/files/uploads/vejibarelivozugidatosovo.pdfIn PDF document text
    • http://gamboeng.com/assets/ckfinder/userfiles/files/javow.pdfIn PDF document text
    • https://hagakure.by/upload/editor/files/54747065582.pdfIn PDF document text
    • https://gameclub.by/uploads/files/mupafa.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/ubdv3rk8f4gssqv2pp2joaat9s/25643980428.pdfIn PDF document text
    • http://skpizzasubs.com/uploads/files/darudosonirafojan.pdfIn PDF document text
    • http://poptheme.cn/uploadfile/files/20210911_221303.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/dc18c22df0056763d0d774b5fdcbd38d/48307891622.pdfIn PDF document text
    • https://optimumquestsolutions.com/ckfinder/userfiles/files/40268522673.pdfIn PDF document text
    • http://quaretti.it/userfiles/files/57926601422.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=virtua+tennis+3+torrentPDF 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_off0000b554.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB554 20216 bytes
SHA-256: 53afb22b75b150553592c01a2a7a83afe65c8a1d5a52a616643c3d9c265e8d17
font_01_sfnt_off0000e91f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE91F 10296 bytes
SHA-256: 2a2837ec3ef4cd9d4cca0b445cf617c6a2cf2f15c4c84acfbc229aa99a1841e8
font_02_sfnt_off0001008a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1008A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1