Malicious PDF — malware analysis report

Static analysis result for SHA-256 89b16bdb5fd3fc2e…

MALICIOUS

PDF

71.7 KB Created: 2021-09-24 19:25:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: aa638b25ca6aee84e2249cd6439cde17 SHA-1: 7964e8d3933117203a513415b88f405ecd89f282 SHA-256: 89b16bdb5fd3fc2e04c29b71454788f99a89053be8503d68601713f2151e3d0a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads and disposable hosting, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The primary attack pattern involves luring users through a malicious attachment to a site that further redirects them.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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 http://z-sinpro.com/upload/files/sofedidexu.pdf In PDF document text
    • https://2acontractor.it/images/file/7498133801.pdfIn PDF document text
    • http://krakowska98.com/zdjecia/fck/file/jusirivan.pdfIn PDF document text
    • http://dawahcity.com/userfiles/file/bojofijonagotukedixaze.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed157f2ee4---77381128132.pdfIn PDF document text
    • http://galettedesrois.hu/userfiles/file/jutimenuma.pdfIn PDF document text
    • http://www.badischer-kunstverein.de/ckfinder/userfiles/files/15304621471.pdfIn PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/62401210750.pdfIn PDF document text
    • http://muntepa.com/userfiles/files/lomidukuxom.pdfIn PDF document text
    • https://transturist.ba/ckeditor/ckfinder/files/files/duganu.pdfIn PDF document text
    • https://adamant54.ru/userfiles/files/fagisazowopexatezer.pdfIn PDF document text
    • http://vitali-schulz-eiskunstlaufen.de/userfiles/files/40648961039.pdfIn PDF document text
    • http://qdjshg.com/files/file/kagikubonu.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b63e694834---90218493970.pdfIn PDF document text
    • http://milkexim.ru/imgeditor/file/podiveninedejagaselog.pdfIn PDF document text
    • http://om-ar.com/userfiles/file/4334628476.pdfIn PDF document text
    • http://kimdaiphatsteel.com/Images_upload/files/37629000882.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/c55c909067150e2946c015a75cfc0be4/vajarasajarifaxed.pdfIn PDF document text
    • http://chinahk-ip.com/chinahk_ip/html/files/editor/file/16989093323.pdfIn PDF document text
    • http://grupafurman.pl/!mag2011/userfiles/file/rudeselerezupejigawijenu.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/92762280772.pdfIn PDF document text
    • https://webmedcentralplus.com/userfiles/file/33529322624.pdfIn PDF document text
    • http://vce34.ru/attachments/file/vemeribege.pdfIn PDF document text
    • https://plagij.at/ckfinder/userfiles/files/84853394743.pdfIn PDF document text
    • http://gerastar.com/userfiles/file/gatulujokuxuxipoza.pdfIn PDF document text
    • http://weiddy.com/uploads/files/202109042037555381.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=structure+of+liverwortsPDF 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_off0000b50f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB50F 17096 bytes
SHA-256: 79c1ab8755415892f5cae50744d83c172dd00353ed090b0592af163bde41cc95
font_01_sfnt_off0000e141.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE141 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f958.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF958 10388 bytes
SHA-256: 378f1c10177700cad3c5a06048ba3d12a44e981da7f127159aad6b2f7ae38b92