Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c0aca1921e8389a…

MALICIOUS

PDF

72.5 KB Created: 2021-09-05 01:18:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 82216757931d7ec1193e67926a2b1d97 SHA-1: 1e96993cf890d4aa986e5fee43e2cc509f8f4b17 SHA-256: 4c0aca1921e8389a25667535b03129ddcd9a7d556a0211466ac6206827582ed9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. Heuristics indicate this is a link farm designed to redirect users, and ClamAV detection confirms it as a phishing trojan. The ML classifier also strongly flagged it as malicious. No scripts were extracted, but the primary attack pattern involves directing users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://synerhu.ru/uplcv?utm_term=paragraph+punctuation+practice+worksheets PDF link annotation
    • http://somsit.com/ckfinder/userfiles/files/10347494931.pdfIn PDF document text
    • https://ottopianos.nl/files/74257581213.pdfIn PDF document text
    • http://ibtaker.ps/userfiles/file/44373510213.pdfIn PDF document text
    • http://xn--80aikni6a0b.xn--p1ai/images/file/jeximimexufu.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/jajifusowuwuzemo.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160e929fa9c6f8---26325455496.pdfIn PDF document text
    • https://sharkovinkom.com/sharkovinkom.com/ckfinder/userfiles/files/lokobudok.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8052644022---zuzutidevupipovajuv.pdfIn PDF document text
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/51934ue0ng9e2bee8nivcchrd9/tifapemodiretimubibeg.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/66961887760d7698200444.pdfIn PDF document text
    • http://bagiez.com/userfiles/file/mixikiguwaju.pdfIn PDF document text
    • http://mu-rrrc.com/userfiles/file/wutisetotud.pdfIn PDF document text
    • https://tjpapigroup3.com/contents/files/41695876481.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/tufukeneselilexafopun.pdfIn PDF document text
    • http://fecoil.com/userfiles/file/koxuxolom.pdfIn PDF document text
    • http://gediklimakinahidrolik.com/resimler/files/59586760624.pdfIn PDF document text
    • https://upaspor.com/resimler/files/wunavowolo.pdfIn PDF document text
    • https://seataclighting.com/wp-content/plugins/super-forms/uploads/php/files/a675147a5e1d62c4eeb1392529ac1787/nupavisubejusu.pdfIn PDF document text
    • https://orangcar.com/app/webroot/upload/files/69945807250.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/sanixamenibajami.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160eca9426b104---takazatimunejuwopu.pdfIn PDF document text
    • http://www.kingsmen-cmti.com/upload/files/lilijofef.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_off0000b987.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB987 16320 bytes
SHA-256: b9ab31b29b4f8748751332a7620b5edd870c904afacbc592fe5136cf7b3d0ce6
font_01_sfnt_off0000e32f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE32F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB46 10888 bytes
SHA-256: 075d14a8983cfea7b7fb9620c830257d496d9c35d178891318f7b26e3d7e7a9f