Malicious PDF — malware analysis report

Static analysis result for SHA-256 481da50b50de7370…

MALICIOUS

PDF

72.7 KB Created: 2021-09-10 22:47:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 63034fab585efbc217533159f1bfcda1 SHA-1: 363c97690b5743b733c485713275bc5fef24ccbf SHA-256: 481da50b50de7370c47b34c3c63e9c798a9e45b5aed3393184c4541ce1e68b98
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external URIs, many pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution lure. No scripts were extracted, but the PDF structure itself is leveraged to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://chcial.ru/uplcv?utm_term=granny+hacked+version PDF link annotation
    • https://pass-eco-energies.com/ckfinder/userfiles/files/gawaf.pdfIn PDF document text
    • http://foxhill101.com/userimages/rodekari.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613341834680d---tipinozubudome.pdfIn PDF document text
    • http://werkkledingverkoop.nl/images/docman/files/63139143488.pdfIn PDF document text
    • https://komunalno.vrgorac.hr/files/59852867386.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/rt0hrltn3stmfh2q5ms28ktli7/61657249217.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/mefejojejudatekameweti.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/57113557994.pdfIn PDF document text
    • http://cc-loges.com/uploads/file/xogomolib.pdfIn PDF document text
    • http://vejwun.cz/images/wopopixilebizawosupaku.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/86002562491.pdfIn PDF document text
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/pabufukipaninezoxaz.pdfIn PDF document text
    • https://kligi.viart.lt/ckfinder/userfiles/files/74316146416.pdfIn PDF document text
    • http://liderzy.natura2000.pl/imgturysta/files/kajov.pdfIn PDF document text
    • http://allasclub.com/campannas/file/remonopasuronefuwego.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/f74c5ebf9e562aac0d51c8a747663f3e/zetujagaruba.pdfIn PDF document text
    • http://wine-paraphernalia.com/files/winep/_repo/file/6099321045.pdfIn PDF document text
    • http://tumwebthailand.com/ckfinder/userfiles/files/doruxe.pdfIn PDF document text
    • http://www.toptehnik.si/images/jibipiwaguniwutato.pdfIn PDF document text
    • http://motovelo-nmsk.ru/userfiles/file/rizejejazez.pdfIn PDF document text
    • http://cctechlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wopugilevutixuzekawe.pdfIn PDF document text
    • https://0955205219.jwa.tw/userfiles/files/wakimijadawiwixubuvama.pdfIn PDF document text
    • http://mtsskzy.com/userfiles/file/20445902721.pdfIn PDF document text
    • http://steakclubhn.com/campannas/file/vosetederixezavakopiv.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_off0000b876.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB876 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d08d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD08D 10636 bytes
SHA-256: 7a9787747964c8e9a104c54459eb43564b8302a5007f23bf34f48c072c620a23
font_02_sfnt_off0000e8df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8DF 17312 bytes
SHA-256: 97b31a5826a58a020525b2f96dace258c035e11051734c7e5bdc8593eacdb428