Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d81fa4b957eda99…

MALICIOUS

PDF

76.0 KB Created: 2021-08-07 11:51:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 8b6b0a2fe48ff24e4155c2ae911760bf SHA-1: 0dc14e72d96f1026e1324793fb9cb54ab2331343 SHA-256: 4d81fa4b957eda99cce3cd51fcf74171d4ca628b48cfd82b5bbc9064cc54f140
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links pointing to compromised WordPress upload storage and other disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The PDF's structure and the presence of multiple external URIs strongly suggest it is used as a lure, likely for phishing or to download further malicious content.

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 https://tims.ro/ckfinder/userfiles/files/tufelelizararaxej.pdf In PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae05e178d4a---98498373610.pdfIn PDF document text
    • https://astdubai.co/userfiles/files/26785005856.pdfIn PDF document text
    • http://ohappy.org/userData/board/file/65442308739.pdfIn PDF document text
    • https://mariapolis.net/ckfinder/userfiles/files/tedodabawejigozuvuxukoju.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/7f27e078e4869c4756e1e3a626758761/fofekoviburulikinerisafun.pdfIn PDF document text
    • http://dentherapia.hu/files/file/99621274859.pdfIn PDF document text
    • https://shevtsov-art.com/uploads/files/gukuwawuloditofogimadize.pdfIn PDF document text
    • https://lemanssrl.it/file/59967198037.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/4956f640fe7c8bff9ed39b7b72252907/mojebuduxogagewid.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/5h2i3om5ccl0lc7nakhefti62l/43659347836.pdfIn PDF document text
    • https://ecole-anglais.com/upload/files/24737991821.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/f37daa3f9cab0d6b3792d16a875a1f31/kiwuxikiwub.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16094a6982cc8a---17081097260.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/c09ded0c0699ca10ecb58f5962081bfc/31355897426.pdfIn PDF document text
    • http://thesetnews.com/images/fckeditor/file/51821761431.pdfIn PDF document text
    • http://gelikonline.ru/content/Files/79305447445.pdfIn PDF document text
    • https://btegypt.com/file/padimu.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16081f0be89caf---63633817029.pdfIn PDF document text
    • https://blsautomation.com/ckfinder/userfiles/files/96654471229.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072f79b28a64---2003577887.pdfIn PDF document text
    • http://ozdesignhouse.com/app/webroot/uploads/files/1547631991.pdfIn PDF document text
    • http://holmeslawfirm-iowa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/86691586350.pdfIn PDF document text
    • https://areicon.com/images/file/7731515335.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=breath+of+the+wild+guide+book+pdfPDF 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_off0000c441.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC441 17104 bytes
SHA-256: 3d551f351b66bf8025aa896034079fe50fa4cd9738ae227022e1d3f1da1e7d32
font_01_sfnt_off0000f0f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0F9 10976 bytes
SHA-256: e33e10a6fb3729e35aea4bb3d7238f457a9293adca98694cf5a761b18d53b7e2
font_02_sfnt_off00010a36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A36 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1