Malicious PDF — malware analysis report

Static analysis result for SHA-256 37ac6843599ef231…

MALICIOUS

PDF

91.6 KB Created: 2021-09-19 10:44:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ac3d2b241642059f17e2945e26ae6275 SHA-1: 53373f78f8605df8dbc8d1ce231f36b3587e63a9 SHA-256: 37ac6843599ef231172e8f79da5312bf4aa91ddfc4a62ebe333ff5dfa496548d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites and other disposable hosting, indicating a link farm designed to redirect users. ClamAV and ML classifiers flagged this PDF as malicious, specifically as a phishing or trojan delivery mechanism. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to exploit users by directing them to malicious or compromised web content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://drafthe.ru/uplcv?utm_term=centroid+machine+learning PDF link annotation
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/h7he54evu8h3n15cvr2q7o84p3/kirotadevagavelowoz.pdfIn PDF document text
    • http://dhleisure.com/ckupload/files/63566997343.pdfIn PDF document text
    • https://pharma-tools.pl/galeria/file/jesolomoxu.pdfIn PDF document text
    • http://ahzgbh.news-read.com/upload/files/93957121738.pdfIn PDF document text
    • http://www.serenissimaservizi.com/files/nidaran.pdfIn PDF document text
    • http://mayinmaunhat.com/upload/files/23705204355.pdfIn PDF document text
    • https://e-room.co/userfiles/file/57136896439.pdfIn PDF document text
    • http://classtool.info/upload/files/25199237262.pdfIn PDF document text
    • http://enslev-anlaegsservice.dk/userfiles/file/kivepi.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/qghcvef0apanu973ra1ri9i4t5/besogibuf.pdfIn PDF document text
    • https://marathonroller.com/userfiles/files/lawupini.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/zuwozovinemebe.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/15276072022.pdfIn PDF document text
    • http://occahomesearch.com/userfiles/files/dabigamer.pdfIn PDF document text
    • http://pelejas.com/IMAGENS/CKFINDER/files/pejibimarejud.pdfIn PDF document text
    • http://www.tivafa.hu/upload/file/99825468492.pdfIn PDF document text
    • http://liebherr-tr.com/userfiles/file/40798228765.pdfIn PDF document text
    • http://xn--eyt274i.com/upload/files/visapil.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613d160113f42---vonigarunaledomox.pdfIn PDF document text
    • http://beergolfers.com/blog/images/file/89841411244.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_off000103e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011bfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BFA 17456 bytes
SHA-256: e25499394807938b7f57d152f38420d288a057d7b4d1088e62d11d910152c601
font_02_sfnt_off00014965.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14965 10680 bytes
SHA-256: 2830555a21afcac9f3f504cd5257e7d1276978efc5083800231bebb5fdb6c6c8