Malicious PDF — malware analysis report

Static analysis result for SHA-256 855d8fc251c2750f…

MALICIOUS

PDF

85.6 KB Created: 2021-09-01 09:11:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6e1f8e59f406881d7bfd2518eee1d5d2 SHA-1: d15c75ca1bb2d47866b5c70565c097001d74f6ef SHA-256: 855d8fc251c2750f752bd39fef3d80c279fff408a83cf24a8c4ecab31980697d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous links, many pointing to compromised WordPress sites, suggesting an attempt to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely responsible for initiating the redirection or download process.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 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://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/25f81be547af732e32d980b4d9ac3c6b/gamalovadu.pdf In PDF document text
    • http://npas.ru/pic/file/75635495998.pdfIn PDF document text
    • http://mehmetrasimmutlu.com/icerik/file/gufoduzinisanogugetofof.pdfIn PDF document text
    • http://istvietnam.com/rich_editor/file/38628595398.pdfIn PDF document text
    • http://cjandjunemillerfarm.com/clients/75830/File/59836065726.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/8205669.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/kevodupegu.pdfIn PDF document text
    • https://silky.ae/images/bulk_images/files/kujoberu.pdfIn PDF document text
    • https://ferropula.hr/files/29435357394.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/a21qs2jqns06k29rjkkcj01mbg/50219928438.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6520d80ea6---49660487905.pdfIn PDF document text
    • http://nfc.soo.jp/file/fufinumo.pdfIn PDF document text
    • https://motodubai.com/uploaded_images/files/95607193651.pdfIn PDF document text
    • http://makesrealsense.com/ckfinder/userfiles/files/44040068421.pdfIn PDF document text
    • http://qataminational.com/uploaded_files/userfiles/files/38614479249.pdfIn PDF document text
    • https://mayurherbal.com/userfiles/file/85391010519.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/fdada2090b484dac48b2bf8096a54924/zoridafukaxusojotip.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/c1c2f1b943697eeec4a87568f7bfa2f9/91118982208.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/42067619463.pdfIn PDF document text
    • http://spzpoz-zdunskawola.pl/upload/file/12980048266.pdfIn PDF document text
    • https://menlopark.com/wysiwygfiles/file/guvedusilawire.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/95501266220.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/3be51bb6662c9d95361fcdbdbd077837/tatelezi.pdfIn PDF document text
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160742bbb54bbd---rifepubikukumokifutegaxa.pdfIn PDF document text
    • http://park-seversk.ru/other/js/ckfinder/userfiles/files/lonuraxazasameroxefamebi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=omegle+video+chat+app+apk+free+downloadPDF 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_off0000e55d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE55D 11168 bytes
SHA-256: 6251f8bbcc8ff1949a13c9d7720fee1f76d33930b7232bf8d7f7b462f860aa2f
font_01_sfnt_off0000ff1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF1D 19392 bytes
SHA-256: 43bc5de23a29a0a87bc40a8b4defc53f4998535f8d0cae506cc794e3e622fa9a
font_02_sfnt_off000130a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1