Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ff09550fd8021ef…

MALICIOUS

PDF

77.5 KB Created: 2021-09-09 05:02:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d6e6413dcf5d93797ac3fbb4e0fd39dd SHA-1: a4c70ba4915e937e1c00dd0facbc682db54181aa SHA-256: 8ff09550fd8021ef308b7ef688abe741eed2ebba04562578079425eb012fbf8b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF 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 delivery through these links. The file's structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://www.kroonzuivel.nl/ckfinder/userfiles/files/sowinulo.pdf In PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/ks85qin67e4gdo5bh9iiesh87h/10028976811.pdfIn PDF document text
    • http://www.sictombbi.fr/ckfinder/userfiles/files/pikumu.pdfIn PDF document text
    • https://noithatkuongthinh.com/uploads/files/45931182260.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/60440363875.pdfIn PDF document text
    • https://presentkompaniet.com/img/content/file/fogaloxadasaruzonu.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/topubadena.pdfIn PDF document text
    • https://doxity.ro/ckfinder/userfiles/files/tawuburawokojojob.pdfIn PDF document text
    • http://poketomecam.com/uploads/files/neviko.pdfIn PDF document text
    • http://toptoptraining.ru/img/upload/file/denafuraxomusi.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/27248045711.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/auhqj4e7vpui58l470rv8pk698/76734751362.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/wubuzotifijebatiraki.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/lubugu.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/topuredenuvipegilesepodu.pdfIn PDF document text
    • https://shunnasato.com/xemigevinarulozup.pdfIn PDF document text
    • https://www.la-melodie-des-saveurs.fr/ckfinder/userfiles/files/9882882921.pdfIn PDF document text
    • https://sardavetri.it/userfiles/file/xavexukoni.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/161372838cab7d---91002758371.pdfIn PDF document text
    • http://askort.pl/Upload/file/74759222034.pdfIn PDF document text
    • https://myshalewell.com/userfiles/file/87733474190.pdfIn PDF document text
    • https://ncsccalgary.com/userfiles/files/nedadekoxigaxu.pdfIn PDF document text
    • https://10playsolutions.com/clients/softklk/documents/_articles_/file/witusevarubal.pdfIn PDF document text
    • http://teresachild.com/upload/files/tixijakogo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=before+crisis+apkPDF 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_off0000c850.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC850 10368 bytes
SHA-256: 3f2f212200dc2c11176240d11b4e0266777da1b0282f12b41efe76614993dabd
font_01_sfnt_off0000dff1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFF1 18432 bytes
SHA-256: 6ef58c9c34cdbe4d475a6e8c7a8f5a30b1a4727c25297e08a047911b1a26cdd9
font_02_sfnt_off00011054.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11054 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1