Malicious PDF — malware analysis report

Static analysis result for SHA-256 6d5311b55cc9e27e…

MALICIOUS

PDF

71.3 KB Created: 2021-09-26 09:59:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c7e69b6da0f6e5dc1c08814e71d993d4 SHA-1: b13a0dcbeea0d3da3c84ed336d35914ea27bc972 SHA-256: 6d5311b55cc9e27e52c01f9c90a653c3daacf19270402898a5a8a5a728f07339
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. Heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and disposable domains, likely serving as lures for phishing or malware downloads. The PDF structure itself is heavily obfuscated, suggesting an attempt to evade analysis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://medvor.ru/uplcv?utm_term=what+is+the+function+of+emulator+in+android PDF link annotation
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/dec4f77699b26c4ad001c30e841d2431/wulezenemepobuvilan.pdfIn PDF document text
    • https://perfecthospital.org/FCKeditor/file/76907414457.pdfIn PDF document text
    • https://99shayari.in/userfiles/files/batagirovokudoparo.pdfIn PDF document text
    • http://ytlcases.com/userfiles/file/zavesigedowazuzaxunuv.pdfIn PDF document text
    • http://auburn-companies.com/userfiles/files/45524450863.pdfIn PDF document text
    • https://springkasteelhuren.be/userfiles/file/wolaba.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143cd2a81047---32287683012.pdfIn PDF document text
    • https://learnrkbin.jugalbandiresearch.com/ckfinder/userfiles/files/bijinimivuwor.pdfIn PDF document text
    • http://alisawedding.com/upload/users/files/forusuwofew.pdfIn PDF document text
    • https://ruxthai.com/ckfinder/userfiles/files/vitinimowajowesatezorami.pdfIn PDF document text
    • http://nationshield.ae/userfiles/files/ramililodowuvuxi.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f262aa9f58---notobatadanonavutiwub.pdfIn PDF document text
    • https://fokusmedia.com/images/uploads/zidobizofib.pdfIn PDF document text
    • http://neogmbh.de/www/sites/default/files/userfiles/file/girotuki.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/99718249128.pdfIn PDF document text
    • http://bulgankhangai.mn/userfiles/files/67427537513.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145525e96dab---mozuturukane.pdfIn PDF document text
    • http://legalinet.eu/userfiles/files/nobeledefujikudapakiki.pdfIn PDF document text
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1613a707c246a9---11045746986.pdfIn PDF document text
    • http://designgaleria.hu/userfiles/file/mogona.pdfIn PDF document text
    • http://matemotors.com/userfiles/file/27135316227.pdfIn PDF document text
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/zizubabajugegavolavak.pdfIn PDF document text
    • http://langyupharm.com/upload/files/rubokabasogalirekusuje.pdfIn PDF document text
    • http://fese.in/ienupdimages/images/files/dutuxa.pdfIn PDF document text
    • http://one9five.com/userfiles/files/fivaropuvamikakigisev.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_off0000b2ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2ED 10836 bytes
SHA-256: a35f795143565cf0ba4ea9633b60fad116cf8fcd0c72a5accc81deba6495091b
font_01_sfnt_off0000cbc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBC2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e3d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3D4 16968 bytes
SHA-256: adaa3e5fd30428e9544376b435566278e6b999ab754303d1d0f1a7656e6ce6e7