Malicious PDF — malware analysis report

Static analysis result for SHA-256 423d9341de26067f…

MALICIOUS

PDF

68.9 KB Created: 2021-09-28 07:56:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 26ecb8bc9b914db6ae35169402ef4a80 SHA-1: db21049376104da9dfad0fcd3bd6108792200fcd SHA-256: 423d9341de26067fc053bf9c83c75ce16d73a598d2b5333b28fe25e511cf7b24
156 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://synerhu.ru/uplcv?utm_term=scaricare+musica+gratis+mp3+per+android PDF link annotation
    • http://wowbond.com/upload/Fckeditor/file/51031093392.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-9/file/pigavusazaxipomagiderak.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/d17e9319fb3ab8935f7f72ee26c926bd/13722997198.pdfIn PDF document text
    • http://vako.vn/app/webroot/uploads/files/40370440723.pdfIn PDF document text
    • http://feldbach-tourismus.at/files/93180760103.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161377b8820069---legifoleruzate.pdfIn PDF document text
    • https://heuresromantiques.com/upload/files/77072026211.pdfIn PDF document text
    • https://pmrmhss.com/userfiles/file/zefuxu.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/sp143o9h5h0q4ujhlbfh0pu1e2/semarozipepabusa.pdfIn PDF document text
    • http://spain-ex.com/images/blog/file/85148104457.pdfIn PDF document text
    • https://lbjgold.in/ckfinder/userfiles/files/mujatoninirajidokozafud.pdfIn PDF document text
    • http://atthaya.com/file_media/file_image/file/13466334594.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202109/file/zajofuvumupiruxonupekob.pdfIn PDF document text
    • http://rejs2013.cycling-recycling.eu/imgturysta/files/sezudujikopedak.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614a3a30e0f06---fatedawetusu.pdfIn PDF document text
    • http://rewitex.pl/userfiles/file/ragexedawumujapep.pdfIn PDF document text
    • http://transporteslaplata.com/imagenes_web/file/66102832531.pdfIn PDF document text
    • http://benhvienlaptop.biz/userfiles/file/79178616457.pdfIn PDF document text
    • http://cycling-software.com/files/file/96803705819.pdfIn PDF document text
    • https://tpijobportal.com/ckeditor/ckfinder/userfiles/files/bapimilefitodiralu.pdfIn PDF document text
    • https://www.abandassociates.com/ckfinder/userfiles/files/letopinuje.pdfIn PDF document text
    • http://ugrctrani.it/userfiles/files/geborudunovafaxabokip.pdfIn PDF document text
    • https://www.restaurant-latableedevercel.com/ckfinder/userfiles/files/69522178833.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_off0000ae4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE4F 11160 bytes
SHA-256: d68d8f67457b02ed63bddabb7f8c0a4ba51d62731929013447f7ef28b0f3432e
font_01_sfnt_off0000c82b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC82B 15000 bytes
SHA-256: fe61ceb3e9d00aa08a21dd94700b28e4a7997f92ca053b1666368420d6b444db
font_02_sfnt_off0000edfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1