Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfef0dc11caab51b…

MALICIOUS

PDF

79.1 KB Created: 2021-09-13 09:03:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3645bee06b227eeb58418f5d9e72bfc0 SHA-1: e482dec7a68b7e2abef040da6906e6784b0d6424 SHA-256: cfef0dc11caab51b23a4af479c4db97f5d48aae027417352a108d8ac016d7f49
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to lure users to potentially malicious destinations. The presence of 'utm_term' parameters in some URLs indicates a phishing or traffic redirection attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://clear-es.net/yamituki-n/uploads/files/taxuvuwejagimolaxaviwux.pdf In PDF document text
    • https://hanakspotrebice.cz/eshop/ckfinder/userfiles/files/nedivisokumuvonidugolewu.pdfIn PDF document text
    • http://prime42.ru/userfiles/files/lerugepifefopusin.pdfIn PDF document text
    • https://soechi.net/userfiles/file/53516011153.pdfIn PDF document text
    • https://lecormier-menuiserie.com/www/upload/files/renofuboxenavune.pdfIn PDF document text
    • http://hairtransplantmangalore.com/uploaded_files/userfiles/files/tevixifataluvisap.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/51796355330.pdfIn PDF document text
    • https://cardolf.ro/files/89924982845.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/93962979524.pdfIn PDF document text
    • http://elfast.ru/userfiles/file/bubovobemeguf.pdfIn PDF document text
    • https://corianderedmonton.com/ckfinder/userfiles/files/68163057902.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/a1e86ceadf715cea1ad5ca5165cdeb5b/zunarazevejowig.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a064155d45---busijeja.pdfIn PDF document text
    • http://elsekmont.eu/userfiles/file/65370330616.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613058ae0ee75---kitotuwi.pdfIn PDF document text
    • https://beauti-full.ru/uploads/files/81272988328.pdfIn PDF document text
    • http://kozhencherrymtc.org/userfiles/file/zabos.pdfIn PDF document text
    • https://istanajpdua.com/contents/files/26032442667.pdfIn PDF document text
    • https://servingltda.com/userfiles/file/44218193962.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/abcaf9c5a38bc41b6dc7833dab3317ad/82941085676.pdfIn PDF document text
    • http://kimdaiphatsteel.com/Images_upload/files/gunupuminobuzigelu.pdfIn PDF document text
    • http://eggtesting.com/admin/uploads/file/lijilafiluxalatiratexog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=tep+tep+app+downloadPDF 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_off0000d438.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD438 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC4A 17292 bytes
SHA-256: 67f8b487bef089c9bf5b1331a5519d5a61d7e6228252260210447145e38da860
font_02_sfnt_off0001185c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1185C 10076 bytes
SHA-256: 415dafab363570a6480f048fb169b4caa3dc23c479853a25686974d5de2aae81