Malicious PDF — malware analysis report

Static analysis result for SHA-256 af21af9aee3a6777…

MALICIOUS

PDF

83.0 KB Created: 2021-09-23 12:00:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: abad28e1e0b90803c796de4e8e414645 SHA-1: b8b80be45f987a22e79b2a1a7c50c9ed043bbd8a SHA-256: af21af9aee3a677738f2efcd1488becda70e90b286fd3eb68420967aca344f52
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and links to compromised CMS uploads, indicating a link farm designed to redirect users to potentially malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://crysiq.ru/uplcv?utm_term=i+want+to+download+free+music+to+my+android+phone PDF link annotation
    • https://unitytradecapital.com/ckfinder/userfiles/files/37762402663.pdfIn PDF document text
    • http://vincitydata.com/uploads/ckfinder/files/xiponerumezewadam.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/j64sccbd9kefe5vpd9gseu52fi/5914870042.pdfIn PDF document text
    • http://yangs-ns.com/ckfinder/userfiles/files/20210912233137.pdfIn PDF document text
    • http://hongdacable.com/d/files/66896983462.pdfIn PDF document text
    • http://jjburgerut.com/uploads/files/2903007835.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/c84457ae2cfdfebdd3d4dc34b9e6ed70/94019405086.pdfIn PDF document text
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/161326e455fb5d---sejuniz.pdfIn PDF document text
    • https://thisissati.com/userfiles/files/57900263871.pdfIn PDF document text
    • http://jyotiacademicpress.org/uploads/file/50301013654.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/kurexafowof.pdfIn PDF document text
    • https://wildarium.com/ckfinder/userfiles/files/jejivakuwemubosubaminujul.pdfIn PDF document text
    • http://doingthing.com/downloads/blog/geust/files/83946800038.pdfIn PDF document text
    • http://boki.hu/editor_up/15397289444.pdfIn PDF document text
    • http://marymo.ru/uploads/files/10514501847.pdfIn PDF document text
    • http://studiotravenzolo.it/userfiles/files/nesokaten.pdfIn PDF document text
    • http://albertf.madteam.net/ckfinder/userfiles/files/jajekojosajizeselekoxun.pdfIn PDF document text
    • https://lifesmart.ro/ckfinder/userfiles/files/walisenepepanojataxow.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0f1db605a---5362550702.pdfIn PDF document text
    • http://ensky-chemical.com/upload/files/54412447014.pdfIn PDF document text
    • https://www.institutvzdelavani.cz/files/kaxowuz.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_off0000dc30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC30 11136 bytes
SHA-256: a8e880120612feb143c1d7565c42211fe623679be40ceb3af63246d629580e5b
font_01_sfnt_off0000f60d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60D 18644 bytes
SHA-256: 4bd8d4f22c5c42501a030885a807468a3cf5a62a99d45d21a8e616b1b1ac7b7f
font_02_sfnt_off00012619.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12619 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1