Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4378f3833e88466…

MALICIOUS

PDF

84.5 KB Created: 2021-09-05 09:38:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 1c7ed6698bf1aaf8b72e4488eb797c2a SHA-1: 69bac375fed2363816d6717ace83612f9e70a688 SHA-256: b4378f3833e884664a28d5897a0b2f4a0cd656bb8d42a99c1e0ec6e0c55b9fc7
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and link farm heuristics, indicating its primary purpose is to redirect users to external sites. Several of these URLs point to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://danielstrehlau.com/userfiles/file/nidadapemeru.pdf In PDF document text
    • http://gioiacompany.net/images/upload/file/81732157902.pdfIn PDF document text
    • https://daleplumbinginc.com/wp-content/plugins/super-forms/uploads/php/files/6be420cae9e66010bd6946227bf04242/58725906857.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b0b79b3ab5---xufeviwetufodopasijurezup.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/181917447834.pdfIn PDF document text
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/5dfe951433eda5866a96d307f321b2bc/donubivawaj.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/767e9f31d4f2f56b7aecab73868f5048/telovewevomizoro.pdfIn PDF document text
    • https://altonika.pro/files/fck/file/81042196836.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf9b084839---bipobimebabuzivufexe.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/8202fa8146138b742d661ac4f106e10d/kugofidobifotetivunutiwe.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc2130f8d2---jamulebiforelizadusosam.pdfIn PDF document text
    • http://osc-pribor.ru/products_pictures/file/20723674827.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/6bee3a28546e6be6a22a1c5b6efa4d1b/25722941963.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9e1acac548---dijawamesafem.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/rabewoxedijofet.pdfIn PDF document text
    • http://cathugo-catamarans.de/res/wysiwyg/file/fevefutuzimogixop.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2a717e717c---34994314145.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/wikexopiwebimavopugisagim.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607ccb3d01958---78842116670.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/f9d8b259ed8761c69a68e350b98eaa84/subulamuzakike.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/c4g325pn353lqp5cs4pbhrmei0/lasuginesesisapifosamomo.pdfIn PDF document text
    • http://robbes.nl/media/files/5679053991.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=let+me+introduce+myself+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_off0000e1e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9FE 10792 bytes
SHA-256: 8f5deb0970b0c55636a2fe5cc2f732db477571395ddc1feb3e829c3e2beb7cea
font_02_sfnt_off000112cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112CD 19068 bytes
SHA-256: e1a45df9ca312c57df59bfc44ccce871e0fe2f9b26b0588376665f2ec895db41