Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b39b9f0727dfcdf…

MALICIOUS

PDF

91.6 KB Created: 2021-09-18 07:51:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 918d6ea8413208555218ebf91ed82355 SHA-1: efe2ba52cbeff1c5e635fa9cd44445a605d68870 SHA-256: 7b39b9f0727dfcdf877f19c32cfed852f70b5a409618189b9124028542b2eb2e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users to malicious content. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest a phishing or malware distribution scheme. The ML classifier and ClamAV detection further confirm the malicious nature of the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://krisoc.ru/uplcv?utm_term=wolowtube+free+online+movie PDF link annotation
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/vukoli.pdfIn PDF document text
    • http://grafitym.kz/files/file/fudewikuzelaboxo.pdfIn PDF document text
    • http://vetusmeter.com/images/upload/File/jivij.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/lpk3fjdkq7vmb87j0oar7ojisu/mezel.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e04b5df791---71762239477.pdfIn PDF document text
    • https://ecosolar-energy.com/piceditor/file/74597248870.pdfIn PDF document text
    • http://champaigncursillo.com/userfiles/file/boxixirowololavadajipebij.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/13392697581.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144f9a74aa42---50587969768.pdfIn PDF document text
    • https://tsafar.ir/basefile/tsafarir/files/fovefugo.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a1fc26b986---11373532575.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/wokinujo.pdfIn PDF document text
    • http://www.forteks.com.br/admin/ckeditor/ckfinder/userfiles/Images/43690236083.pdfIn PDF document text
    • http://e-restauracion.com/app/webroot/files/uploads/files/24885371413.pdfIn PDF document text
    • http://xn--h1aaebajlcgx.xn--p1ai/sadm_files/97678554529.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/rezilatunelidob.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/77900039219.pdfIn PDF document text
    • https://apluskleaning.com/admin/images/file/5354212924.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/xufuni.pdfIn PDF document text
    • https://semut73.com/contents/files/vupenak.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/93164148572.pdfIn PDF document text
    • http://novo-foto.ru/ckfinder/userfiles/files/delixanudipuranepopasa.pdfIn PDF document text
    • http://aldobini.it/userfiles/files/gosuwepi.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_off00010448.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10448 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011c5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C5F 10432 bytes
SHA-256: c369d6409e47068aca81ae4c6be154a1da3a1116c072957e1df3fd3d82f355f2
font_02_sfnt_off00013403.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13403 17228 bytes
SHA-256: 4e6ecbe85584c859088a17af0dbe1657d4717df775a92ff022ea5f99052af11a