Malicious PDF — malware analysis report

Static analysis result for SHA-256 98639dd9d259cdfc…

MALICIOUS

PDF

90.9 KB Created: 2021-09-15 17:17:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 158da339998040bf230f63aa9218e127 SHA-1: 7f21a91bbeced33ceb7ea92e54af4d5ee0da1d80 SHA-256: 98639dd9d259cdfc260a43055b71cd25524f935c473f172fbd4b4c429426a0a1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous URLs, many hosted on compromised WordPress sites, which likely serve as a link farm to direct users to malicious content. The document body is heavily obfuscated and unreadable, but the presence of external URIs and the link farm heuristic strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://medvor.ru/uplcv?utm_term=java+in+a+nutshell+7th+edition+pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2a5127ea3---77223416218.pdf
    • http://kursverwaltung.fit-n-essen.ch/ckfinder/userfiles/files/wikafupunopidudiwi.pdf
    • https://calprin.com/ckfinder/userfiles/files/52196158224.pdf
    • https://malashealthcare.com/userfiles/files/dimamabuzamos.pdf
    • https://supportsystemsvainc.com/home/ssvi/public_html/ckfinder/userfiles/files/tezeroropuz.pdf
    • https://clic-essc.ch/ck/ckfinder/userfiles/files/29733974337.pdf
    • https://samuelben-horin.com/userfiles/file/41531249315.pdf
    • https://cristalparkhotel.com.ve/ckfinder/userfiles/files/6143120881.pdf
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/508e1348252d041d72cd23f193979e34/34239612635.pdf
    • http://acunambalaj.com/adenoto/upload/files/27129644087.pdf
    • https://minhgianggroup.vn/upload/files/lusexif.pdf
    • http://weilandvloeren.nl/fckimages/2237427028.pdf
    • https://conexusinternational.com/ckfinder/userfiles/file/tosarasakazanisanonope.pdf
    • http://xn--80aer5aza.xn---42-5cdakyymnnb9ake1az.xn--p1ai/ckfinder/userfiles/files/palotugimafukomifobobid.pdf
    • http://zdrowejaja.com/Upload/file/91530736679.pdf
    • https://goldfieldssanddrags.com.au/ckfinder/userfiles/files/22073672432.pdf
    • https://millinerandassoc.com/files/file/rawujesegogojitol.pdf
    • https://nsck-cykelmotion.dk/userfiles/file/mesewadapajukus.pdf
    • http://jkbprivateiti.com/userfiles/file/jebejenopozunagubami.pdf
    • https://ginecologmuresan.ro/ckfinder/userfiles/files/fotizozifotirivajuzi.pdf
    • http://fanghsin.com/uploads/files/202109140059054575.pdf
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/k85k2shpu9h9evt76ehflud9h3/28817960869.pdf
    • http://familiehollander.nl/images/uploadedimages/file/kixepatureganuzobixonipu.pdf
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1613dde988d2d7---22428087945.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fcdf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCDF 16792 bytes
font_01_sfnt_off000114f1.bin
5ae2c95a261f83f599afff284714834671924eb47684904f89f38a2641bb5bc3
pdf-font-stream PDF embedded font (sfnt) at offset 0x114F1 18788 bytes
font_02_sfnt_off000145a5.bin
b047837587eb22e7f7219679000328f393a8010e5b29d29c2c39ebdae9e12df3
pdf-font-stream PDF embedded font (sfnt) at offset 0x145A5 10704 bytes