Malicious PDF — malware analysis report

Static analysis result for SHA-256 66d410d22e8cf1a3…

MALICIOUS

PDF

85.9 KB Created: 2021-07-17 00:11:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: a11b3011f9b30b384ae09b1f3716da5a SHA-1: e37fc4a981384c9f78d312e14ce89389ca124d19 SHA-256: 66d410d22e8cf1a31b326d77953fd2378c25d09e301a609f6870a1e8f456e917
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by multiple heuristics as malicious, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The PDF contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm likely used for SEO poisoning or phishing. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://humanitool.ru/userfiles/file/42780489325.pdf In PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077fa3c945c6---37561697314.pdfIn PDF document text
    • https://medtek.vn/storage/file/2571500586.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/zapatefemiwigukoxib.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/6fe2a0d074b3e8c585c5452089b44df0/foniweludanejukibugi.pdfIn PDF document text
    • https://divetechmarine.com/contents/files/xiwalezulopavubutarula.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb24e45601---nuxusa.pdfIn PDF document text
    • https://gangwontaxi.com/FileData/ckfinder/files/20210707_EF4F36300027F06A.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16078114e91fe2---59007743482.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/2798e161821e9040f7a0862d79906c98/80249317519.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/acb55b3bcf22cba7bdbbb44ff2569cae/latufumulezujukupifana.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abf75da9e94---varikibutiremujuboz.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/fomigamexubabofufis.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608668417b817---sejavivapave.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=eat+well+for+less+breakfast+muffinsPDF 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://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_off0000ec8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC8A 10776 bytes
SHA-256: ad81a0b71d9f4c3f3fcc1f8933169948e88710622239f56f0ba4d8bcbcfde380
font_01_sfnt_off00010569.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10569 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D7B 16848 bytes
SHA-256: 076f0677760369017fc2d74b140d72df0739c0dd893254488d41b82cdd6d9c85