Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c3d1fb50d90cfa0…

MALICIOUS

PDF

79.7 KB Created: 2021-09-16 23:46:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 312f70a10592560f2ddb7389e006594d SHA-1: b31bab8254b54db42c008fd0924d6955eb5cc4af SHA-256: 4c3d1fb50d90cfa08738f6bb5ad07baf9cc2976086610c1f29e547444845d78a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this is a malicious link distribution mechanism. The ML classifier and ClamAV detection further confirm its malicious nature, likely used for phishing or to serve further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://huntic.ru/uplcv?utm_term=poco+x3+pixel+experience PDF link annotation
    • http://wignaccent.com/FCKeditor_2.6.3/userimages/file/20210908235607.pdfIn PDF document text
    • https://samsungdvm.net/upload/ckfinder/files/saliv.pdfIn PDF document text
    • https://rsvforum.com/userfiles/file/39352000520.pdfIn PDF document text
    • http://wingmanplanningdemo.com/userfiles/files/nuzovudivovubi.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/ecf2e945ada4a842f8adee0b0ea1fa2d/woganavuvolusom.pdfIn PDF document text
    • https://pilot-nav.com/ckfinder/userfiles/files/45426175147.pdfIn PDF document text
    • http://sartoriaventurini.com/userfiles/files/62986318030.pdfIn PDF document text
    • https://nocenzura.space/web/img/podborky/files/jijivipemeroximabeto.pdfIn PDF document text
    • https://bahispesinde.com/gnc/veri/_files/suluxinebazi.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614314ce6bec1---18399247885.pdfIn PDF document text
    • https://rosebankprimary.co.za/inc/ckfinder/userfiles/files/rafodikuzimosor.pdfIn PDF document text
    • http://soleilboo.com/images/uploads/files/miritobolomawan.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/o7jhnuvp0s3vbbac1ipr5cilsi/4831546578.pdfIn PDF document text
    • http://interreg-ipa-husrb.com/downloads/7349738583.pdfIn PDF document text
    • https://euinsuti.uniluxgym.ro/app/webroot/files/userfiles/files/delakidasesaf.pdfIn PDF document text
    • https://bestofbucerias.com/upload/file/gezonufemiguvuwibexo.pdfIn PDF document text
    • http://csc-021.com/userfiles/file/20210915185606_cu2e54.pdfIn PDF document text
    • http://bbmeti.it/userfiles/files/vobomunomu.pdfIn PDF document text
    • http://mediacast.vn/ckeditor/upload/files/pibokivaxaf.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/sd9nnk31fhgbpqqton2k3hb6ul/forarabiropomawo.pdfIn PDF document text
    • https://charteriraq.ir/basefile/charteriraqir/files/64181000191.pdfIn PDF document text
    • http://ippinnudon.com/uploads/files/87948013392.pdfIn PDF document text
    • http://portalcom-b2b.es/img/user//file/_0197943001630757785.pdfIn 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://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_off0000d2e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2E4 18220 bytes
SHA-256: 5fe18b53f6845e9baa35597138dec3304758834207bba2c2e4c1238eba382b92
font_01_sfnt_off00010247.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10247 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A5E 10212 bytes
SHA-256: 1cafc32f2eca4c534a0f336ee7b220b15ff62b4521f9b8c0814f725ca2bff1bb

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