Malicious PDF — malware analysis report

Static analysis result for SHA-256 75b11ea3ddd5a6c1…

MALICIOUS

PDF

76.6 KB Created: 2021-09-19 08:35:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2cc904b7dc2fa67805e02fbee796fb8b SHA-1: a2e16734b3407c118ac12fcd79e45c708bad56c5 SHA-256: 75b11ea3ddd5a6c134a84ca503b6dcd1c1029ea287b2414c27776e4bd2d6aace
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Numerous embedded URLs were found, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://crewmak.ru/uplcv?utm_term=subway+surfers+hack+with+unlimited+coins+and+keys PDF link annotation
    • http://precisao.net/files/files/rewujemuguvu.pdfIn PDF document text
    • http://tavaszitura.eu/userfiles/files/jumomivupupafenejodo.pdfIn PDF document text
    • https://usssecuritate.ro/userfiles/file/72612999805.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16146a265ba3a4---98231154148.pdfIn PDF document text
    • http://nessium.fr/userfiles/file/32906628556.pdfIn PDF document text
    • http://dorinhawear.com/admin/fckeditor/editor/filemanager/connectors/php/fckeditor/editor/filemanager/connectors/php/userfiles/file/kenuwiso.pdfIn PDF document text
    • http://seattlebestteriyaki.com/uploads/files/47383009268.pdfIn PDF document text
    • http://bienbao.net/uploads/files/toxojefenopafuseje.pdfIn PDF document text
    • https://ourcampuswindow.com/ckfinder/userfiles/files/riwoko.pdfIn PDF document text
    • http://debten.net/UserFiles/File/44039751614.pdfIn PDF document text
    • http://www.perchegouet.com/ckfinder/userfiles/files/15023698636.pdfIn PDF document text
    • https://eirai.org/editor/ckfinder/userfiles/files/dujujebukanixodewelinipaz.pdfIn PDF document text
    • http://surveycook.com/upload/tmp/202109/file/14430755866.pdfIn PDF document text
    • https://tennis94.fr/img/pics/files/xokene.pdfIn PDF document text
    • http://tecsun-moscow.ru/docs/file/77506375234.pdfIn PDF document text
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/1bbbd9d94127c4e76e3619f026b0ec19/77492591613.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/16224372588.pdfIn PDF document text
    • http://sakurahoaanhdao.com/webroot/img/files/ribipiretalaboneju.pdfIn PDF document text
    • https://gizaviation.com/uploads/files/ziripurewubogararojekomar.pdfIn PDF document text
    • http://robbes.nl/media/files/63100103348.pdfIn PDF document text
    • http://studiocalcinoni.com/userfiles/files/buwoleka.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/fbgfr87kic73i2o3sd5okm1sk2/jidew.pdfIn PDF document text
    • http://avon-bratislava.com/files/files/11981310039.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_off0000c5a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5A9 11348 bytes
SHA-256: db4effacc89f21143ff713629b0c8745f363fdc4e5add96038e6ac36f54a6e24
font_01_sfnt_off0000e03f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE03F 17048 bytes
SHA-256: 2ced436d25d73f13f558bef35d69e01c12dcfd4b2f3356e61be21cee172a0928
font_02_sfnt_off00010c0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1