Malicious PDF — malware analysis report

Static analysis result for SHA-256 36ad171db0c9adba…

MALICIOUS

PDF

81.9 KB Created: 2021-06-07 05:21:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 505c8571d0c3cb0eb29878b10af3fa84 SHA-1: 723ecbc8696fe0522e16de288fc604f3161d8895 SHA-256: 36ad171db0c9adba7d46eac652b9c161fd85faf227c0665e1a69eb5c93b88405
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many hosted on compromised WordPress sites, suggesting a phishing or malware distribution campaign. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and 'evaluation', indicating a potential lure. No scripts were extracted from this sample, but the extensive use of external links points towards an attempt to redirect the user to malicious content.

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://krisoc.ru/uplcv?utm_term=evaluation+polygones+cm1+pdf PDF link annotation
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/3e754d24b5de83425c835f047f63fcfa/tapanefunuvomu.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9fbace76fe---barika.pdfIn PDF document text
    • https://bawwabatrizq.com/userfiles/file/66754391207.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16081921ea7d11---61831992923.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/folotepetuwirarapenofe.pdfIn PDF document text
    • http://olimpic.hu/ckfinder/userfiles/files/bovopepovitijusanavunag.pdfIn PDF document text
    • https://careersourceokaloosawalton.com/files/public/67194642199.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb85d0cc38---logunuxofonuzup.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b32ec54b2d9---38624724870.pdfIn PDF document text
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608319fd915d0---20147153348.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/0jv7a0m38tfv0glr3le595iqum/58065126018.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16075a7a1a421c---24235936480.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093e7600afa7---lipitezafa.pdfIn PDF document text
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/6a1eee8aae7b79e2fa4cfc9b4dceb9c6/muwekezokepir.pdfIn PDF document text
    • https://olivier-daulte.com/ckfinder/userfiles/files/95955231543.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/57374449489.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/b6j555jk2o0r5957fmitkathr0/terag.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/81a42118b29b896af4313e0849c51d47/62733756422.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ffd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFD6 5552 bytes
SHA-256: dfccb6638e0fc601c82b6c08af071ba7a2bfd45ef55521fbd7fc7cc60a91d5d6
font_01_sfnt_off000112d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112D1 12200 bytes
SHA-256: 3d0d3b4a9283bfc39fbd42915d9c89ff10fdcaa7998842c7c68e6167b14e563e