Malicious PDF — malware analysis report

Static analysis result for SHA-256 3cd1a35723aaad91…

MALICIOUS

PDF

87.7 KB Created: 2021-09-01 12:47:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 06b54c6c4b59bbdc1f617632c1c402aa SHA-1: 6f035d68eb334e7ca831a7ec539cf3ab22946da9 SHA-256: 3cd1a35723aaad9190140e5112e725416cc4bce9a1679a12956834e934e8c45b
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to lure users to malicious destinations. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is used for malicious redirection. No scripts were extracted, but the sheer volume and nature of the URLs suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 5

  • 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://chcial.ru/uplcv?utm_term=simplifying+polynomials+examples PDF link annotation
    • https://workinhotel.com/upload/fckfile/79518219624.pdfIn PDF document text
    • http://parbatsamajjapan.com/img/files/files/sunol.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/80826956916.pdfIn PDF document text
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/b5e1a3c7b4234fc2fe43b7769777f5b4/83795626319.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160898dbd419bd---80194269697.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/bd06ffdd783333b0b296439ff39391f1/jizivuzixiberenafomotoxe.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9df21836a---50264582261.pdfIn PDF document text
    • http://carrozzeriabosini.net/userfiles/files/91868512233.pdfIn PDF document text
    • https://stealthwindow.tw/uploads/files/202108211735497910.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/jitujoz.pdfIn PDF document text
    • http://envisystem.com/upload/userfile/files/mifaribajerarofe.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608bc82a8a4ed---2551211246.pdfIn PDF document text
    • https://www.gpaci.org.br/cms/ckfinder/userfiles/files/31324701402.pdfIn PDF document text
    • http://apnorajasthan.net/userfiles/file/83018103876.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/wedipuzuvimamuluzivizile.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/27301053215.pdfIn PDF document text
    • http://styliststudios.com/imagesTE/file/fupekadar.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/timejajokalanatovulamen.pdfIn PDF document text
    • http://jplus-ag.com/upload/files/BodyFile__60ECA78D1D420.pdfIn PDF document text
    • https://manajrgvaaradhi.com/cms-uploads/files/ranumipefimukerememive.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/55685515686.pdfIn PDF document text
    • http://charontrade.hu/data/file/gefarirupebekozuz.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/4eau1o3o7n7iv30mbc2peq7rcc/64806748043.pdfIn PDF document text
    • http://gezond-trakteren.nl/kasteel-doornenburg-img/bestandenfile/57100265160.pdfIn PDF document text
    • http://siamintertrade.com/file_media/file_image/file/58786666733.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_off0000e760.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE760 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ff72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF72 21856 bytes
SHA-256: a673955d2c94dbf4d334ca50006354d230c4cb362acfbef05617756cbf523fa9
font_02_sfnt_off00013744.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13744 10796 bytes
SHA-256: bcde89005f53c7e5eeaa14ebef18165fab77bc8a1dad0954a7b0f29c012fd257