Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d3fdcfe3d55eb17…

MALICIOUS

PDF

72.8 KB Created: 2021-06-19 12:03:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 938b14fa9be05b9fa5078415bacd1be6 SHA-1: dccce5496ba1981ab027b850a9c21321ff9dad6e SHA-256: 3d3fdcfe3d55eb1794bcf3010632c7cb6b13d1edfc61d1c127fb33ee2eee15ab
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload directories. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the URLs point to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b65925b8a8---mepibisuxadaribazagi.pdf In PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160807bf9d0cce---rogekuzev.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa77d824bb---xonigudebajulowenabum.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079bce6b2fc1---10739552392.pdfIn PDF document text
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/85104147819.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/ac6c083653f519cdc2483d8d9089f726/xibaw.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/16070e407c2b2f---44143203760.pdfIn PDF document text
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/9ueg2ri5f002v24o65p72kkd8h/31522800415.pdfIn PDF document text
    • https://ratco-hardware.com/Ups/files/wobugokadodeko.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608fcaa7ccccb---28849382262.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160ccd75557c69---vekedidipegaba.pdfIn PDF document text
    • http://24cvety.ru/upload/files/sobafagudu.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/51502860220.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090993f7f65d---3310383763.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/3be5d8710a4ba0e8ae9c14f3e48a78ac/68880227180.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/f70e6268a5cbdf2b8d5185aeff8614e5/novigezipojexidagebafosol.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/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=possessive+adjectives+picturesPDF 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_off0000e017.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE017 5172 bytes
SHA-256: 416a47308ee705e98239382c86157733058402fae9dbb3d313d732a096ad3ebf
font_01_sfnt_off0000f1d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D0 10944 bytes
SHA-256: 53321976a1b9c16eb2799bcabea514545622f4c2d4208cacfb3af79b857c5208