Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa641c18738c8928…

MALICIOUS

PDF

70.7 KB Created: 2021-09-25 17:30:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1b0c936abc685bb75dfb4524078878b8 SHA-1: ec00185f420ea38558c2ac25190676bb880b3d17 SHA-256: aa641c18738c8928f4b4782d27ccadfe34d7805b0520e946e80f022757104c46
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm or phishing lure. The ClamAV detection and ML classifier strongly suggest malicious intent, specifically related to phishing. The document body is heavily obfuscated and unreadable, providing no direct content-based clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://zgic.ru/!upload/files/dimelorep.pdf In PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613e3ab99cc2d---85521038815.pdfIn PDF document text
    • https://krzczonowice.pl/gfx/file/gonet.pdfIn PDF document text
    • https://ecowaytechnologies.com/ckfinder/userfiles/files/zoriloni.pdfIn PDF document text
    • https://samavetpharm.com/userfiles/files/romajorudugefalijib.pdfIn PDF document text
    • http://abnicum.ru/files/file/sowexofexuniwojag.pdfIn PDF document text
    • http://teplorium.su/userfiles/file/kuzewuwakedalazisexos.pdfIn PDF document text
    • http://mastervin.ru/files/file/21449126502.pdfIn PDF document text
    • https://icbacademy.com/upload/files/15202136107.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144c056acb25---83047705192.pdfIn PDF document text
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/14010934290.pdfIn PDF document text
    • http://ewhamd.net/upFiles/ckeditor/files/tabuwuwizewaruxefunirafor.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/64300474428.pdfIn PDF document text
    • http://alltimescare.com/attachment/files/vuwelidu.pdfIn PDF document text
    • http://tcihk.com/userfiles/wuduwatojujilalot.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/julikumowezanuvuvo.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fead6a8d8f---nuzowemoxed.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/16140699bd0054---82643251518.pdfIn PDF document text
    • https://fond.ru/userfiles/file/nisepegufozeneja.pdfIn PDF document text
    • http://anipetkingdom.com/webroot/img/files/62165554958.pdfIn PDF document text
    • https://s-serviss.lv/userfiles/file/88235479773.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/452587ee0c3b7aa2541259102639afd2/noboxi.pdfIn PDF document text
    • http://parbatsamajjapan.com/img/files/files/89963434605.pdfIn PDF document text
    • https://eletvital.hu/uploads/files/sulatevine.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+save+word+file+as+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_off0000b429.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB429 10532 bytes
SHA-256: 8c8716d9fe5599d10aa2d18afda55daa443e7bc9fbf97c2b5962b07970dcc105
font_01_sfnt_off0000cc48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC48 16060 bytes
SHA-256: d6685fde8d9c79c03302d993aab26febe2a7656dd1738e779d33a550f57e64bd
font_02_sfnt_off0000f4dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1