Malicious PDF — malware analysis report

Static analysis result for SHA-256 25552f8d407bc274…

MALICIOUS

PDF

74.5 KB Created: 2021-09-19 23:20:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 17dd7c22139f90283b2dd46133395510 SHA-1: 6e112cfe12349ae46629d0d4588dc9e56c8e9d5c SHA-256: 25552f8d407bc274eb6196f80aeb7c4b1e8c30390a2ccf5af1b9d5e049de4bfc
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs and links to compromised WordPress upload storage, indicating it is designed to redirect users to potentially harmful content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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=the+originals+putlocker PDF link annotation
    • http://leylasuren.com/images/userfiles/imagefile/47590553382.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/doset.pdfIn PDF document text
    • https://360clothing.in/home/www360cl/public_html/uploads/images/files/morutupotanawobajolodita.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/kuxomanumaforatebutasev.pdfIn PDF document text
    • https://hirurgija.me/files/fuvikowati.pdfIn PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/24961479874.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16139b4dc85e2f---nogudixajemavujubo.pdfIn PDF document text
    • http://maxbrio.kr/files/files/putizamefejagesalesuxotu.pdfIn PDF document text
    • https://toppelletmachine.com/d/files/11302986857.pdfIn PDF document text
    • https://www.sherpachristain.org.np/ckfinder/userfiles/files/6276447601.pdfIn PDF document text
    • http://harringtonandlombardi.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xokuxozupizil.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161416d4dd9ea5---reburibul.pdfIn PDF document text
    • http://turchifiltri.com/userfiles/files/senekemazedofalatow.pdfIn PDF document text
    • http://bibliotekaszamocin.pl/img/upload/files/pevufovatoxasavufano.pdfIn PDF document text
    • http://xycrusher.com/d/files/2435555338.pdfIn PDF document text
    • http://kxqcgs.com/filespath/files/20210909140017.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/35452381775.pdfIn PDF document text
    • http://noithatdangcap.vn/app/webroot/uploads/files/3446073889.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec5995cfea---nazalajulevaridamulo.pdfIn PDF document text
    • https://viettincapital.vn/upload/files/mepotalatubasi.pdfIn PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613d51c387949---fisibixa.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/aaf1c0769e96c927cf70607fdc588914/39993516854.pdfIn PDF document text
    • http://lutechmed.com/Images_upload/files/49616862790.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_off0000ba47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA47 19128 bytes
SHA-256: fa714f346f5df667c4f71e0d40fe0572a050cca05ee6ad6592ab9fb4c6dda1af
font_01_sfnt_off0000eb61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB61 10808 bytes
SHA-256: 4551c0ca5e2dc5dae607b6b038fcb849b4dcb138a843535582d30aedff26eea0
font_02_sfnt_off0001044f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1044F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1