Malicious PDF — malware analysis report

Static analysis result for SHA-256 b16918d7d2b663be…

MALICIOUS

PDF

105.7 KB Created: 2021-05-12 07:05:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: ebf4629dea2ec0b29aa3a33ecdc28646 SHA-1: c386db1fe92207ddf4f9c72014c2569e03a89293 SHA-256: b16918d7d2b663be42b3475e389ae17be5ef501fbb6e038568400adb35026e64
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised websites, likely intended to host malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the structure and URL patterns are consistent with phishing or malware distribution campaigns, often initiated via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609215a1c2a91---32515220628.pdf In PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/160772f05122df---labematejobusukuge.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/a6c1eedc8c9467ec6fc0a74a283079d1/defoxibi.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081a6a14473c---seminipikul.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c923c3b14c---12878237089.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/b844ddfc52f2cb843fcf3a10605360bd/gezunuzafurupufirabif.pdfIn PDF document text
    • http://nedirajtebosnu.net/userfiles/file/79818103276.pdfIn PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/ar609fth2c89bje21r2u29c424/girafasojejomuz.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/804f7ea77ef93e25814a02c8a80f9cc0/giwapada.pdfIn PDF document text
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/34b640be15402abfcb14fc7310580a90/15808851903.pdfIn PDF document text
    • http://aisef.org/uploads/userfiles/file/file/manunimalofewulijur.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097508b7942e---fabenedalikede.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075b815c43e9---virabirurajokujenuwore.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/zMnd8XtcwSM/uplcv?utm_term=paris+bus+map+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_off000148cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x148CF 5296 bytes
SHA-256: 57316046f229844e6d01eaaeb24d3820f2ae3a9e8e5e304a43ca0afb0ef317d8
font_01_sfnt_off00015ab2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15AB2 12784 bytes
SHA-256: 23d5cb461d190c333fec0c65a753d6a1398899cb1f604e05b26fe035c56a9023
font_02_sfnt_off000183a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x183A9 16140 bytes
SHA-256: 3f83bbfb2e03141a9083badfb1da6e2b1773f9aa6b1ed8f30fc2d392a5ee3553