Malicious PDF — malware analysis report

Static analysis result for SHA-256 663ce580ea7d9387…

MALICIOUS

PDF

69.0 KB Created: 2021-09-05 12:16:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 05a62100b5f73fe2f3e4f5774286158c SHA-1: 95804ec40cf738a2889ea6146b04e6a98f0ca8ce SHA-256: 663ce580ea7d938787d9e97406d92a0330cf13a6738dd8d4989a5f0c0daf6a45
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs and link farms pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution campaign. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating the PDF is structured to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://drafthe.ru/uplcv?utm_term=managing+conflicting+priorities+pdf PDF link annotation
    • https://locktactyuma.com/userfiles/file/bekuvenen.pdfIn PDF document text
    • http://cyuanmei.com/userfiles/file/93679066488.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/82c0fc10d439a3255a38d2209d55a2c2/melofusesoruwatuwefimo.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/7089343555.pdfIn PDF document text
    • http://fst-uinsu.net/userfiles/files/rofefafopopopobupawezo.pdfIn PDF document text
    • https://bacninhonline.com/webroot/img/files/geguzovot.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/roperewovobezipog.pdfIn PDF document text
    • http://www.deopendeur.org/imgUser/file/sizumuduxilosako.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/54797754042.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/0eb37321bd095a990e34239c30afc3bd/ferab.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c12a3e59c05---sewikivojozumuk.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/e46569c255d2484c4010485d9bce81ef/62999381425.pdfIn PDF document text
    • http://agro-pasz.pl/ckfinder/userfiles/files/87455970624.pdfIn PDF document text
    • https://digireg.it/upload/55310334038.pdfIn PDF document text
    • https://menuiserie-sainte-anne.fr/userfiles/file/gegazijo.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/ba27ecc7a620ffc1e9e4ca054cb7cdd1/pomopiseselutabuji.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e34e2b46cd---pefami.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/31071616804.pdfIn PDF document text
    • http://btc-ltd.com/upload/file/30348114172.pdfIn PDF document text
    • http://thietbixanh.net/uploads/files/58083658436.pdfIn PDF document text
    • http://xn--80aamdqpfpr.xn--p1ai/upload_picture/6758234020.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_off0000afc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFC4 15448 bytes
SHA-256: f8f3de834660d753fad441e3b7a69257f18356e24b5f287d9bf382edd6bb6be1
font_01_sfnt_off0000d5eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE02 10788 bytes
SHA-256: 214a218c7a850eaa4af9ba16c6b720c59474325e39fa4ad174cba8bc1ca6bcea