Malicious PDF — malware analysis report

Static analysis result for SHA-256 d31b6051403ed7a5…

MALICIOUS

PDF

70.5 KB Created: 2021-09-16 01:12:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 651e71f306eaa3c7b0457c81fac691c8 SHA-1: 742b3df9ae90b962460f38f106113b9ddd08be32 SHA-256: d31b6051403ed7a54a19d3dae8f461face779e74f8a3becdda20a1a9118b2133
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to compromised WordPress uploads and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and embedded URIs strongly indicate a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://ketchas.ru/uplcv?utm_term=how+do+i+block+restricted+calls+on+my+verizon+cell+phone PDF link annotation
    • https://atlaskvartir.ua/data/uploads/files/64908909653.pdfIn PDF document text
    • http://pathtojanna.com/userfiles/files/munifutunebalimojepanuwe.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/vasikiledarajegitujomam.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109122147428929.pdfIn PDF document text
    • http://biomehl.com/images/content/files/549848062.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142481c5fbdc---vabevetenajukosawipija.pdfIn PDF document text
    • http://isspskola.lv/userfiles/files/61286532696.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/4tjouurcsv724jmg4nqn6evcar/31264567360.pdfIn PDF document text
    • http://15449010.com/FileData/ckfinder/files/20210910_2AE3E2099E5C9E4A.pdfIn PDF document text
    • http://murielbellhomes.com/userfiles/files/18195399728.pdfIn PDF document text
    • http://lscapital.it/images/file/gubiledepek.pdfIn PDF document text
    • https://buffinvestment.com/upload/ckfinder/files/17853740243.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140ff0fb9176---83056677211.pdfIn PDF document text
    • http://bayanairag.com/uploads/userfiles/files/43112817058.pdfIn PDF document text
    • http://studiorapizza.it/userfiles/files/lozatopemapewojunapite.pdfIn PDF document text
    • http://www.cafeinca.com/img/public/contenido/file/kojokokovapesopurawi.pdfIn PDF document text
    • http://rubella2.integra-sh.com/userfiles/file/bopojiwuzuxa.pdfIn PDF document text
    • http://netichikawaya.com/userfiles/file/5164958842.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d6421859b4---94095670378.pdfIn PDF document text
    • http://droprint.my/home/ququ4923/public_html/userfiles/file/lolapu.pdfIn PDF document text
    • https://benhgout.net/uploads/Files/file/12252646301.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_off0000b396.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB396 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cbad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBAD 11328 bytes
SHA-256: 36b01712f3189a182f1556eb6516a20c117112ca8212708a1981215b0b4fead5
font_02_sfnt_off0000e5f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5F3 15084 bytes
SHA-256: ca418efabf7e8de3270564e0e0f7dd705b79655a2937bd75a4286a134dbe0b3f