Malicious PDF — malware analysis report

Static analysis result for SHA-256 57bd5f2731ca3790…

MALICIOUS

PDF

90.7 KB Created: 2021-08-13 17:11:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0f2344324e666a41873450b895677cb8 SHA-1: b1ce3554f9845784cf9322e379879df138fb98b4 SHA-256: 57bd5f2731ca3790ae6135db349d76ea02f6522b60ecdee2aab4ef0992fad2b7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to potentially compromised websites, indicated by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://epplast.com/files/file/xetupubezefatukipeva.pdf In PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607f491236e43---xatanatu.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/113445daf75edf0dc8511c1067cbc35c/38772583574.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/6k25hp032sac4krhmsi8rbqbgi/benelumedumisiliga.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160826e9a8abb9---jajuxipizale.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/lqge9d6ctlhig2iv9lgkp96qtp/73168032609.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16082ae5227596---37578881366.pdfIn PDF document text
    • https://partner-support.net/user_data/userfiles/files/99038511567.pdfIn PDF document text
    • https://juniorclublivorno.com/sitonews/images_upload/files/66983079812.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/160766c30665e8---wivuwoxeri.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/6c87148b707ac8a92b753885a204f49a/majevitemedika.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b170c4769a7---63991089110.pdfIn PDF document text
    • http://ray-king67reunion.com/clients/41562/File/29845161100.pdfIn PDF document text
    • https://global-product.org/CKEdit/upload/files/baposokelakadumiguno.pdfIn PDF document text
    • http://aucoindeshalles.com/menu/file/99286587622.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160901b36290f0---nakufawob.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1417023c29---42039955750.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/5f6023369d38440a51ff16f42d6a423c/ruduvow.pdfIn PDF document text
    • http://smartdeal.pl/files/upload/files/gebojojekovitivovonuwovu.pdfIn PDF document text
    • https://kopari.hu/files/file/wesuzikatidopejarisige.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160be436692025---44327110676.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/felufujebin.pdfIn PDF document text
    • http://cuatudongnhatrang.com/uploads/files/mofidefog.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae8c71c02dd---bavudavafeken.pdfIn PDF document text
    • http://portalcom-b2b.es/img/user///file/_0594625001622797673.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=citroen+c4+grand+picasso+owners+manual+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_off0000f97d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF97D 11256 bytes
SHA-256: 14fe85c943d5f76b2106ee0a093a5bc375fa29b09bddcc7b3feb25a95d3cd893
font_01_sfnt_off000113cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113CF 18980 bytes
SHA-256: 7ac896f0c67d6c2e5dda11390e8696c45bab5ae7d4b59361dc5f8713e047da32
font_02_sfnt_off00014290.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14290 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1