Malicious PDF — malware analysis report

Static analysis result for SHA-256 55fd470dc0d8c1a9…

MALICIOUS

PDF

72.5 KB Created: 2021-06-23 08:06:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 27cfcd619c1b49311bca3ed485f91ea8 SHA-1: fa7be5716d8b3214e81e39127104fc67f5ed70c3 SHA-256: 55fd470dc0d8c1a971226194782c9662b9fedeb451468ee6f0651b134fb76463
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, indicating a phishing or trojan threat. It contains numerous links, many hosted on compromised WordPress sites, suggesting a link farm designed to distribute malware. The document body is heavily obfuscated, but the presence of URLs like 'https://philabc.ru/uplcv?utm_term=nox+insufficient+disk+space' implies a lure related to system issues to trick users into downloading 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://philabc.ru/uplcv?utm_term=nox+insufficient+disk+space PDF link annotation
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160896c4a384a4---65470059833.pdfIn PDF document text
    • http://growlink.biz/userfiles/file/wosef.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cafaf3bb5f---18865401219.pdfIn PDF document text
    • http://caythuocdangian.net/images/files/mekobavewi.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607de1a43ec88---xalamodemalerebiku.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/16092e36aa4a78---zesesegapevewowodat.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9360a56ae6---govapamerorigezi.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/4336bcee07d5fb1788c3acc2a5bcae15/zomebepag.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/ehc86gmkjhqovltdu3918sess0/leduxowino.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609331bd18437---nanudapizumafezugefedinus.pdfIn PDF document text
    • http://yuhenganquan.com/userfiles/file/20210603101212_1796111362.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file/%5C/2021060112023795.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160b29b5e7e7af---jevuwene.pdfIn PDF document text
    • https://fcksa.com/ckfinder/userfiles/files/65059403224.pdfIn PDF document text
    • https://cakenepal.com/userfiles/file/99882413444.pdfIn PDF document text
    • http://adacu.org/userfiles/file/20210622220343.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/4abe6d9da5b724b1801021d823b621fa/80464230801.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_off0000df6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF6E 5124 bytes
SHA-256: 3e13eead35a38a48daf013ec558e923be03319041c5519f8730d0d60982b3bb5
font_01_sfnt_off0000f104.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF104 10540 bytes
SHA-256: 03c08b5438685814148484d757939d5fe3a3ff514afafefc0d9d6ba50c2edebd