Malicious PDF — malware analysis report

Static analysis result for SHA-256 efc3f70e85787235…

MALICIOUS

PDF

87.1 KB Created: 2021-08-08 22:50:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 997e88c39cdfcbafbfa4770e6c5ff783 SHA-1: a499cb9f3c10f567be2cd7065900e2e7a74b9cc2 SHA-256: efc3f70e85787235d778d8116b7ab5d3c39831a1752529a4e184843c3f2e16f5
164 Risk Score

Malware Insights

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

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains embedded JavaScript and numerous external URIs, many of which point to compromised or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of embedded JavaScript indicates an attempt to execute malicious code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/n22h3l4j2il1cu6qc1optaqdg2/49121262283.pdf
    • http://enidbtwcreunion.com/clients/5/52/52e94d62e82ff66504c7d921fc07bf70/File/29357478354.pdf
    • http://nt-module.ru/ckfinder/userfiles/files/dimujasasubibodesizo.pdf
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609601e7ddf3d---selef.pdf
    • https://rubin2000-distribuitorshop.ro/userfiles/file/87324156886.pdf
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609a6ac7e22a2---28945995386.pdf
    • http://thunderstar.cn/userfiles/file/20210503203638765044185.pdf
    • http://www.sport-konyv.hu/userfiles/file/tepavafuposerexejamifeg.pdf
    • https://mednet.mk/public_html/upload/userfiles/file/sojowumapixi.pdf
    • http://dungcumaymoc.com/Images_upload/files/biwenalawosuwudinodinabi.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/tb40216nuiv05boav0ihr4kdh0/repakonibizetimoj.pdf
    • http://incomsistema.ru/ckfinder/userfiles/files/90900071785.pdf
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/lapugupunoseva.pdf
    • http://beergolfers.com/blog/images/file/lasip.pdf
    • https://kuzeyilac.com/resimler/files/najoranufazakowazorow.pdf
    • http://francisfamilyreunion.net/clients/870293/File/47794934719.pdf
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/1fe68faa9a8756fd7264021a07881750/bezezurupijiruvotirowe.pdf
    • http://studioarclab.eu/userfiles/files/93045408694.pdf
    • https://imad0c0.com/js/ckfinder/userfiles/files/6230480229.pdf
    • https://coil.hk/upload/files/sibarolesek.pdf
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609c41b54f7eb---dugaxagozujaruledo.pdf
    • https://lusagroup.mobi/images/website/user/files/34676102314.pdf
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16086290bb607f---74283816596.pdf
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16089513f2c781---lufedameve.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=variable+costing+and+absorption+costing+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_off0000ee2b.bin
b65054ac44cb293cedd33459b60e54e2487f4c55cd8e14794368f47d770ab059
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE2B 17996 bytes
font_01_sfnt_off00011d02.bin
aa6cc420991e86cd1de75863df77a8efe79fb2d002395d3ac7a54d5c4044ace9
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D02 10904 bytes
font_02_sfnt_off000135f1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x135F1 16792 bytes