Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5557ab36466af77…

MALICIOUS

PDF

79.8 KB Created: 2021-07-09 14:53:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 2822e1809e8855f07bcc84e4841f206e SHA-1: 2eababbbf151fb1ad44241d5b05971690f4e0a61 SHA-256: c5557ab36466af7715e0964b6926953c4223ecbb7366e19266d2653606dba925
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the presence of external URIs and the overall structure point towards a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://philabc.ru/uplcv?utm_term=how+many+valence+electrons+in+each+group PDF link annotation
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/815e90a0bbaa38ab81d33b8745c4dd9f/36044876668.pdfIn PDF document text
    • http://teplospectr.ru/images/files/42222226645.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/wezejabugonibu.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071046565b77---50036778242.pdfIn PDF document text
    • http://biurod9.pl/public/userfiles/file/nebolefuvemiso.pdfIn PDF document text
    • https://grup-insaat.com/userfiles/file/fexolovenifewego.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d13911a88---91928890380.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d2214f2e50b---85959987626.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/9be697a2adabd53189eba6ffcdb62313/nunesekofidaravaju.pdfIn PDF document text
    • https://yptea.com/data/fckeditor/files/93975191162.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/gdpb0i54cnqqht0846k9vaj5ej/99027938585.pdfIn PDF document text
    • http://gleneaglehoa.org/images/file/nawodosirifovebu.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609f2481a51f5---91067606654.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/3a9c800ac6e38fd498649201298710d5/51906210328.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/uvsnqcierbcdevpjo53doat8r4/3140724294.pdfIn PDF document text
    • https://markeishahall.com/wp-content/plugins/super-forms/uploads/php/files/48d6dd11a235637525d537602fc1125b/1334090998.pdfIn PDF document text
    • http://dekoblickfang.de/userfiles/file/losasid.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/rezixizododuwuxirov.pdfIn PDF document text
    • http://vanharteyoga.nl/uploads/files/55724690122.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/88532148495.pdfIn PDF document text
    • https://www.ppmcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/qoeqdk6654hqp59ba0tqvqais1/76061544311.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/3fc2d3d1bfdf4b20755d16001e74e033/gafapuxuk.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/cogqqnci0tl8mial7f1sb1ag0e/jedome.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e763693d328---fosogaratovajo.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_off0000d3a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3A2 16912 bytes
SHA-256: 9308b1f82c43b2a67593a5bd9ec89bd38bc9fb099d5917e2ab07e22b73b49b6b
font_01_sfnt_off0000ff9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9A 11176 bytes
SHA-256: 040f9e3dd7eac21b5188bc1e53d9d4305e5e72158bb7103800c84c959e61e1c9
font_02_sfnt_off00011994.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11994 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1