Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf4d5356c617fa99…

MALICIOUS

PDF

82.8 KB Created: 2021-09-17 10:17:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 3bf703d244147046a679408db6cbf2f7 SHA-1: 538ab9f1280f41d2ed47e6c1c100b09579e08e0f SHA-256: cf4d5356c617fa99846cd629d75ccae22b97cb213d2012c5080af8ff746853de
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to various domains, many of which appear to be part of link farms or compromised content management systems. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs suggest it's designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • 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.
  • 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://chcial.ru/uplcv?utm_term=candy+crush+windows+7+free+download PDF link annotation
    • http://amongelite.com/ci/userfiles/files/ruforatakovi.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/ad96e69c6e5d42bb93dafde199c564e2/19893062437.pdfIn PDF document text
    • https://www.marjojaspers.nl/ckfinder/userfiles/files/fotewepiga.pdfIn PDF document text
    • http://iphysiology.ru/upload/nupavivufotojine.pdfIn PDF document text
    • http://4x4autok.hu/userfiles/files/wugepokutuw.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/lajopotude.pdfIn PDF document text
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kokigupewo.pdfIn PDF document text
    • http://louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/mubiwixajowalinaz.pdfIn PDF document text
    • http://beganijewellers.com/ckeditor/ckfinder/userfiles/files/niwubagezezomebojiri.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/424ece10a9920ce435d5419d813fdcbc/46795890463.pdfIn PDF document text
    • http://thietkewebbacninh.com/webroot/img/files/kozenum.pdfIn PDF document text
    • http://bahtiyardishekimi.com/fckfiles/file/62518653667.pdfIn PDF document text
    • https://iveducentar.com/uploads/assets/file/89740889044.pdfIn PDF document text
    • http://dachastyle.com/userfiles/file/51915190547.pdfIn PDF document text
    • https://inmaabiladi.com/userfiles/files/93229528877.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/zegaw.pdfIn PDF document text
    • http://stadtbild-intervention.de/Quansis/ckfinder/userfiles/files/77639696769.pdfIn PDF document text
    • https://kga-am-adlergestell-ev.de/kga/ckfinder/userfiles/files/pukatujubagegazalapifiwu.pdfIn PDF document text
    • http://magnumprint.ru/upload/files/76386354606.pdfIn PDF document text
    • https://scalping.ir/data/files/file/bukadoputiva.pdfIn PDF document text
    • http://olddieselparts.com/ckfinder/userfiles/files/putarogagufegifugived.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/16134d27797dfa---72694556355.pdfIn PDF document text
    • 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_off0000dfe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFE4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7FB 10856 bytes
SHA-256: db1c74edcf938a8f236fad1569c4c74f1db4203f34fdc51aec2a925bf29fb609
font_02_sfnt_off00011120.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11120 17392 bytes
SHA-256: 4f97e21b095fa09820d9a5931212bb06ffd200f0249cb227d1c95d275f67bc83