Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c135bbde2cf9de3…

MALICIOUS

PDF

82.3 KB Created: 2021-08-19 10:07:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 454cbb8dfd24e9fc90af135a27765112 SHA-1: f6df6a7a1b136e6bdd14f21bb749bb4dfb439dba SHA-256: 7c135bbde2cf9de391bf1d09038116a800e279b823890b4bc5776a9ab341a691
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the presence of external links points to an attack pattern involving redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://crewmak.ru/uplcv?utm_term=subject+verb+agreement+multiple+choice+quiz+with+answers
    • http://abogadosaguilar.com/ckfinder/userfiles/files/tufokiv.pdf
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160823bc224347---zebepenowagasijabotamef.pdf
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160fdfa220e96c---bedulenovegonomidezukebo.pdf
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/nuxapifamesekabop.pdf
    • http://rwdwebwebdesign.com/img-aim/files/88219502718.pdf
    • http://samilove-payitforward.com/clients/f/f9/f9b0b202ed5d2cb263a89f8a9bd08a94/File/pudifenuxekutov.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/55c4ee37ee51a045cd8b314d42263729/bedojejoputitajedon.pdf
    • https://investincarpathians.eu/app/webroot/media/files/52936227373.pdf
    • http://delta-serwis.pl/pliki/2202486753.pdf
    • http://ohmamakitchen.com/uploads/files/bikonatomug.pdf
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8bd17471ec---buwegabuvedilexesafif.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089f7889d286---dozuxamudavojero.pdf
    • http://conblocmanado.com/pics/file/85897625155.pdf
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1611b8426ccbef---xuzatizugo.pdf
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089bd072e937---7186735714.pdf
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/luxifikerifekageti.pdf
    • http://safetypath.net/cms_images/wavapolowijonerebazaxiv.pdf
    • http://sandsflooring.co.uk/ckfinder/userfiles/files/28265432143.pdf
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/emfoiqocn6qrl93l014oipc27j/22428768021.pdf
    • http://ndt-ultratech.com/files/65153361944.pdf
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608888562b758---kitebazelabap.pdf
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073be0ce47e2---rumumuxiwibasumil.pdf
    • https://vanrun-it.nl/userfiles/files/68271949310.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/0juruullt62c9nsuuvnh95p1r5/warag.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_off0000db3c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB3C 16792 bytes
font_01_sfnt_off0000f353.bin
ca5545005e481e63aa4eb3866a9178755d60fe22bfa9664db9eb57fd4dc308a2
pdf-font-stream PDF embedded font (sfnt) at offset 0xF353 11624 bytes
font_02_sfnt_off00010e49.bin
9816808cf7d71755665949434e876a1d9b60b54e660a1918b9e7f90f00700fe2
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E49 17052 bytes