Malicious PDF — malware analysis report

Static analysis result for SHA-256 83c412754e6d5cb5…

MALICIOUS

PDF

72.6 KB Created: 2021-05-02 21:52:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 73de4ae3107250ba458aff517ca29d48 SHA-1: 4d696bd6885b7192ad1b34b325ccc689945a4c33 SHA-256: 83c412754e6d5cb51be1201fd39a7fd2559ce540f7d0fbc3316f1da27e8ed8cb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress sites, suggesting an attempt to redirect users to potentially harmful content. While no scripts were explicitly extracted, the nature of PDF link farms often involves embedded JavaScript to facilitate redirects or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.truegridpaver.com/wp-content/plugins/super-forms/uploads/php/files/ec467bedacd126ac3dd5d6ecdb07bee4/vonodij.pdf In PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072f355685d9---9783072846.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086fe3ee30c0---tojolivibafiled.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076b337617e5---minaridabujanunir.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081973be75a2---kikilapiwaju.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/cf9b84b509820cfeaecd84d2921ff24f/gojikidivuxaxoneguxo.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607afdf818664---toperaluliwerawibidadop.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071b3e2f353a---jelaj.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608604f450c38---25914905890.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/9at7i2lq50ccmvbjhl25dks06j/givaxiwirumamafatime.pdfIn PDF document text
    • https://apinero.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b3697290bc---19682793628.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b94ad31d7c---wesuvijaxowawokonunuteze.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/ldv6tp8dl07i00f7adud8on9l4/gopekorudu.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608926dad8399---rabajevot.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1607768c82fb4a---jesopisakolikoravefu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=how+to+disable+bixby+android+9PDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF55 5340 bytes
SHA-256: a96546973fd965be004efd45014742c92cdb44951d9c1c17f844f558745f1c7b
font_01_sfnt_off0000f199.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF199 10460 bytes
SHA-256: b40b82e9b32a3f0e62b938da2d85f9610b7d780a1fd46e62d2cfec8f3b28a5fa