Malicious PDF — malware analysis report

Static analysis result for SHA-256 c70f11ab8f4a4780…

MALICIOUS

PDF

78.0 KB Created: 2021-05-02 08:47:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: adb9cb4b16d305e77d02bc256585c43f SHA-1: 4acd3f9eea91ef9ba13fd51a39378686a7cdf4c1 SHA-256: c70f11ab8f4a4780ffc783a684bebbc04d5f44c3279aa59a20cb6101ab7f87d2
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 reveal it functions as a link farm, directing users to multiple compromised WordPress upload storage locations and other potentially malicious sites. The embedded URLs suggest a phishing or malware distribution campaign, likely using the 'vocabulary for ielts academic pdf' lure to entice victims.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/20f9239492e1b18723604616dbac9235/52399440973.pdf In PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1606ff7dc33945---97037045224.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/81607955d65e54cd59ed423da298a9a7/59742713049.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/0hetbsblgu450h997del1h5bv3/bumazetujozozidak.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/757bdc1b55e99608fc93bf7941998626/fexunogefoleni.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/1dc7905ae1f25a3f558b93be1fe4b55e/gipegobe.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160805dec51194---fobasaguboz.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/tizatalajatopav.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/f69e087b7f6b2370bcffd353b40a6cad/88466377384.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/4374f66a0f62507564a222f5cd0d9e06/bekigofovuwikunefa.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16077252b4fbdb---37661528.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16071e09613269---sokaluf.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/BkSY9tpko7c/uplcv?utm_term=vocabulary+for+ielts+academic+pdfPDF 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
    • 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_off0000d227.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD227 5508 bytes
SHA-256: 434e15f2bd2bd12b037e324095474a182ba26955f578a17eaf81d4a180e9ff21
font_01_sfnt_off0000e4d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4D5 21100 bytes
SHA-256: aba3dc2428dafe29dab86100ac61480f36d8fbee9b2ce8ac844b311d5f36c477
font_02_sfnt_off0001146b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1146B 16120 bytes
SHA-256: d1c8684a1a3d898794fb67da7698232674cbd89070737fd881b584d0545c9aac