Malicious PDF — malware analysis report

Static analysis result for SHA-256 5184aa7681d37ab7…

MALICIOUS

PDF

70.2 KB Created: 2021-09-14 03:28:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b8cda9a4efe9be83134c8e0f4335ca05 SHA-1: b6418dd79293686e45f3a3dc20da9d0de2d4bd16 SHA-256: 5184aa7681d37ab7d9835e0a4fe0754ee9f4fc4b0e6e731ea00bee348c21c8bf
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are flagged as part of a link farm on disposable hosting. The high ML score and ClamAV detection strongly indicate malicious intent, likely to redirect users to download further malicious content. The presence of external URIs and the PDF's structure suggest it's designed to exploit user trust through deceptive links.

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://tese.in/ckfinder/userfiles/files/judepewivuk.pdf In PDF document text
    • https://dongciao.com/uploads/files/202109061327034908.pdfIn PDF document text
    • http://ambulatorioveterinariocigliano.com/userfiles/files/ramujixamevivefivurej.pdfIn PDF document text
    • https://cliniquemyo.com/userfiles/file/pixulupubotowisadebu.pdfIn PDF document text
    • https://playerpress.com/ckfinder/userfiles/files/43111224719.pdfIn PDF document text
    • http://bagliodeimille.it/userfiles/files/bilomuw.pdfIn PDF document text
    • https://topinsolventa.ro/userfiles/file/gogevamakitudazadubemevuv.pdfIn PDF document text
    • http://consulcongress.it/uploads/assets/file/33809685756.pdfIn PDF document text
    • https://gfwofficial.com/ck_imgs/files/gimopeviruluzelefogonuw.pdfIn PDF document text
    • https://nls.vn/upload/files/13572603862.pdfIn PDF document text
    • https://carlojans.com/cms/file/52137214338.pdfIn PDF document text
    • http://samurairamenbar.com/uploads/files/suwimivifusutadewezeg.pdfIn PDF document text
    • http://balaton.varosom.hu/userfiles/files/pajigukuwopi.pdfIn PDF document text
    • http://nawooelcs.com/upload/userfiles/2021/09/files/210904093316.pdfIn PDF document text
    • https://kuzeyilac.com/resimler/files/popekubaredujizibu.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/8815897081.pdfIn PDF document text
    • https://tahuacoop.com/cms_gpadmin2015/sgi_userfiles/userfiles/files/larifusefivef.pdfIn PDF document text
    • http://shinex-auto.com/userfiles/file/25386596761.pdfIn PDF document text
    • http://imhkayseri.com/resimler/files/17793770338.pdfIn PDF document text
    • http://czernavendeghaz.hu/admin1/file/medagikezivez.pdfIn PDF document text
    • http://architettosbaffo.com/userfiles/files/91233872587.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/161390108db059---91309504048.pdfIn PDF document text
    • http://teedinmaesai.com/user_img/file/xugexufojiniwasilutami.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=dim+screen+androidPDF 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_off0000b31a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB31A 10388 bytes
SHA-256: 67df3085d241b0f6a8fcaefd55cbaddfd526108c2100447de1776fe420c02286
font_01_sfnt_off0000ca88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA88 16324 bytes
SHA-256: 8322e2df9b7ddf64f5aa7aa8f23b64db50f0bdd7196f8359ce2038325864f5b3
font_02_sfnt_off0000f3ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1