Malicious PDF — malware analysis report

Static analysis result for SHA-256 9857de4dbc9ff809…

MALICIOUS

PDF

74.1 KB Created: 2021-09-05 18:12:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 18e6ce494c50de9d80eaf528a3f0e73f SHA-1: b6c2c2580a41d2a70bcc30b9647903d5715edb89 SHA-256: 9857de4dbc9ff809d54968d2d57dbf224429a4cc609cabf6f649c5d37d740494
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the structure suggests it functions as a link farm, potentially leading to further malicious content or exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://archissimo.eu/userfiles/files/42714132237.pdf In PDF document text
    • http://bougerpourstarlight.org/clients/c/c6/c668404594a1c08d975ab50c7bec58f6/File/24828364152.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///roraxezaguzipebofevibin.pdfIn PDF document text
    • http://zjgjqmr.com/v15/Upload/file/202182144161800.pdfIn PDF document text
    • http://ms-beauty.com/ckfinder/userfiles/files/9735633962.pdfIn PDF document text
    • http://xn--80ahcjevtqq.xn--p1ai/ckfinder/userfiles/files/mofopokiguvebobimurid.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/84726920563.pdfIn PDF document text
    • https://www.caissedesecolesdu5eme.fr/backoffice/ckfinder/userfiles/files/80954457601.pdfIn PDF document text
    • http://etrustmi.com/ckfinder/userfiles/files/59918150003.pdfIn PDF document text
    • https://rajaunited.com/contents//files/fozut.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/r0kl76sepua1ilgfa2uq5906kb/67509348140.pdfIn PDF document text
    • https://realxenon.ru/uploads/files/nuzeripusawesetaluduwodej.pdfIn PDF document text
    • http://studionegro.net/userfiles/files/tipogodujadokitujug.pdfIn PDF document text
    • http://szwygs.com/upload/pakefif.pdfIn PDF document text
    • http://rs-entp.com/upload/file/kenuburo.pdfIn PDF document text
    • https://trimix.bg/UserFiles/File/95262545892.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/tq0u8qblqvd5dhcc358ojcgq43/kifuvigiziramizon.pdfIn PDF document text
    • http://www.offshoreyachts.net/web_upload/editor/files/jiwazaluwubuzume.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7db29ff13---tikuruloruse.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1610f710640506---63540537932.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c331e10bebf---5285779051.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=collins+easy+learning+german+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_off0000be25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE25 10888 bytes
SHA-256: 3a677ef72f8f9ffaf608a9eea589c49d3e7fcbaaaf15f5bffdac472e86a31cfb
font_01_sfnt_off0000d720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD720 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF32 17480 bytes
SHA-256: ddd5f8723cc9f8ee8ae9eb80030e2e790b00df35c8ad8c6e4cc3b3541871ef26