Malicious PDF — malware analysis report

Static analysis result for SHA-256 371316d51a90f545…

MALICIOUS

PDF

83.8 KB Created: 2021-09-01 04:53:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: 43078b88d4205bbdc225a129559b0aad SHA-1: 8ccc4286396dd8234be62b7d42cfa12a77d99b9b SHA-256: 371316d51a90f545683cb0c43980b1a8ed229bd66b8ca2d896c84537a2a12f7a
224 Risk Score

Malware Insights

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a seed-phrase/secret-recovery lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Recovery secret / private key request critical SE_SECRET_RECOVERY_LURE
    Document requests recovery phrases, private keys, backup codes, or saved passwords. Requests for these secrets in a document are high-risk.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://robwalker.net/fckupload/file/77144371545.pdf In PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ade6197fd95---34672939134.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/467ed0df4dcc743944f056a8b2f39225/65898238770.pdfIn PDF document text
    • http://stin-verdon.fr/assets/Image//files/52473178508.pdfIn PDF document text
    • http://benhvienlaptop.biz/userfiles/file/16456459139.pdfIn PDF document text
    • https://marwaautorepair.com/nbloom/fckuploads/file/63110386042.pdfIn PDF document text
    • http://gdgom.com/upload/file/210628123708432757kzjghdh3guo0.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607f67d9ace4c---27340116546.pdfIn PDF document text
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/da04647780433a0c18689d5a3567e8aa/diverirevi.pdfIn PDF document text
    • http://fiumevivo.it/userfiles/files/dozip.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/3bbr6051u4ti5s78v0rc7a0qa4/wulujefawinofiwufepej.pdfIn PDF document text
    • http://freetds.net/userfiles/file/61021039474.pdfIn PDF document text
    • http://tantex.org/tantex/tantexuserfiles/file/kekedadarusazan.pdfIn PDF document text
    • http://jacsonsfurniture.com/userfiles/file/60172618122.pdfIn PDF document text
    • https://inks.bg/userfiles/file/89749317764.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/769k9lj0723h2v73pn4s0jgsq2/bifebuxuluxigadoravad.pdfIn PDF document text
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/4d97a223a9c506d85a74ee7cb0ee7fc9/96444089452.pdfIn PDF document text
    • https://www.rongoldmanlaw.com/system/js/back/ckfinder/userfiles/files/75825129071.pdfIn PDF document text
    • https://www.djluk.co.uk/wp-content/plugins/super-forms/uploads/php/files/18abnkm2odsrokrqedib7qe9eu/zegupasozibutegalef.pdfIn PDF document text
    • http://msamerica.net/clients/873634/File/24067386655.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608825576842b---nezumazaj.pdfIn PDF document text
    • http://bakkervoorwinde.nl/app/webroot/files/ckeditor_files/files/zarogigujuvijinisu.pdfIn PDF document text
    • http://ros-grad.ru/fck_editor_files/files/kelekujelokojapowatilagok.pdfIn PDF document text
    • http://pantryscan.com/123cars/imagefck/file/25949555013.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/tigodol.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/avsf2db1ns3id4s745i9q4tdn6/96306582725.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=short+notes+for+gate+csePDF 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_off0000e24b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE24B 18040 bytes
SHA-256: e29a0c8072c8a7ebc582b1faf99f8cd221d94bd2adfaae3eac14ee8c897decdc
font_01_sfnt_off0001111b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1111B 10552 bytes
SHA-256: 532ea78262a1048625f4397a4300381f6fff0b19bc7943344342165da62ed269
font_02_sfnt_off00012925.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12925 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1