Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5b4ba4d28db57d6…

MALICIOUS

PDF

70.1 KB Created: 2021-09-24 16:12:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5161f4d6c47783d2c27c1e8ed92c8ce3 SHA-1: ae90596ee73ae09867ebe24c25ccc936e2458d2c SHA-256: c5b4ba4d28db57d6f1766f7033a2ede95759e68bcf1432c2ee63cf952d1259b3
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the extensive use of external links and the nature of the hosting suggest the document's purpose is to drive traffic to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://infrive.ru/uplcv?utm_term=best+android+ww2+strategy+games PDF link annotation
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130d6d20e5ed---jivazesalodekiwevimotatu.pdfIn PDF document text
    • http://picart-personal.pl/fckupload/upload/file/56978059267.pdfIn PDF document text
    • https://jimsdelibrookhaven.com/demo/jimsdeli/admin/userfilesfile/84773755528.pdfIn PDF document text
    • http://bayernglobal.de/userVZ/file/digivizabo.pdfIn PDF document text
    • http://megaprestige.ru/uploads/files/vaxazil.pdfIn PDF document text
    • http://travelci.ru/ckfinder/userfiles/files/podaloredajerape.pdfIn PDF document text
    • https://abriganature.centralcms.cloud/galeria/files/75244889982.pdfIn PDF document text
    • https://chilepools.com/contents/files/raroxalilitan.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/21253695008.pdfIn PDF document text
    • http://qlionshousing.ca/userfiles/file/morobikukevefofibafafu.pdfIn PDF document text
    • https://qpshouse.com/upload/image/file/73308449213.pdfIn PDF document text
    • https://www.sudoku-cool.com/ckfinder/userfiles/files/kilika.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/16132c41c3a706---94731562666.pdfIn PDF document text
    • http://vinczeandlaszlo.com/upload/xokikupitepa.pdfIn PDF document text
    • https://shevtsov-art.com/uploads/files/ferefunifamik.pdfIn PDF document text
    • https://anzhero-sudzhensk.verlauf-ekb.ru/admin/ckfinder/userfiles/files/3044725305.pdfIn PDF document text
    • http://unibox.lv/files/text/xurunagigibo.pdfIn PDF document text
    • http://myjobcareer.net/userfiles/file/2021092216191373499.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/fawemozukenuvodidaderap.pdfIn PDF document text
    • http://elskenecologie.nl/files/67499280154.pdfIn PDF document text
    • https://pastravariaizvoarelebratiei.ro/images/file/95089195239.pdfIn PDF document text
    • https://cafemocion.com/userfiles/file/sufibaxigepujijuvaxa.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/161491d72d7a4a---69357975403.pdfIn PDF document text
    • 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_off0000ae4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c666.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC666 10916 bytes
SHA-256: 6388fa9f992923135784b15c76db9e154a4976641cdd9edb21b8ae728efae8ef
font_02_sfnt_off0000dfa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFA0 16616 bytes
SHA-256: f4333b9dc09d6ba4e95c199d49f6ba2aacff8b9b5aeadc39e9cd5d8dd23cab06