Malicious PDF — malware analysis report

Static analysis result for SHA-256 55d7aba9329e95b5…

MALICIOUS

PDF

68.5 KB Created: 2021-06-19 10:46:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 87f22f84774abec73872431decbac964 SHA-1: 8d3f0c5a17c07df5002bab8c475bde594dcc0b34 SHA-256: 55d7aba9329e95b57afb453c8fc5fb73ea46bf8f9630354e3f8fa8cac16c6ef6
176 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier with high confidence. It contains numerous links to external websites, many hosted on compromised WordPress installations or disposable domains, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, contains metadata related to wkhtmltopdf, indicating it was likely generated programmatically to appear as a legitimate document while hosting malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/1606d354f0db4e---24943460820.pdf PDF link annotation
    • http://glotecgh.com/upload/editor/file/maxapitagosoradodusebosu.pdfIn PDF document text
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/07d3724d8df01e480487b3a635bba6f5/pejiwejagegofumugafugedef.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608848487a5e6---nozemuvezutifozudotaviwe.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/a12a8a621877426519e3bb80618076e9/57041532923.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/359fb5e1351a35fda82c2739c0d2cc6a/guxeroseruxolukudapufezal.pdfIn PDF document text
    • http://huile-de-nigelle.info/userfiles/file/webepufetekikova.pdfIn PDF document text
    • http://darec.sk/files/files/jipuzukadaluputu.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/67ef0b1e4d10b998a77f6c841b404dc8/32780114138.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8e1c9815a9---23771621044.pdfIn PDF document text
    • http://youngshiny.com/userfiles/file/1621207391.pdfIn PDF document text
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084c1bc313be---95902645374.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/2ae8802db76aebbfbe9ab45588ffd3f8/36274573961.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=spring+time+piano+sheet+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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cde2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDE2 5524 bytes
SHA-256: 88df3f0fe662c11884c6eb3f82d52af0729c0eb749eed372ace89fb340c9a882
font_01_sfnt_off0000e083.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE083 10864 bytes
SHA-256: 0ee54966fee1bb2107cd1a9c0133a499c7daa8f792015750bb993d77381889be