Malicious PDF — malware analysis report

Static analysis result for SHA-256 21675f7a4d9d85e6…

MALICIOUS

PDF

83.5 KB Created: 2021-09-03 07:15:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5436a19251d3e290d333891e83b6c53d SHA-1: d13cc60a3373476f14c29252ca34a263ac9f1e43 SHA-256: 21675f7a4d9d85e6b202765cb23cf2782fe3659251438fd188a51eec85c369e0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to distribute malicious content. While no scripts were explicitly extracted, the PDF structure and embedded URLs indicate a phishing or redirection attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://nutricionintravenosa.com/wp-content/plugins/super-forms/uploads/php/files/4ba066617a497f09496bae0571a8df2a/45204655001.pdf In PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160820dbd11413---33101465983.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/58128862194.pdfIn PDF document text
    • http://sapthagireesyathra.com/userfiles/file/vunuzajitorojasokinawuz.pdfIn PDF document text
    • http://tischlerei-schlusche.de/sites/default/files/file/rowudifok.pdfIn PDF document text
    • http://tnmetalworks.com/images/files/zojudorabozibedirogu.pdfIn PDF document text
    • https://nnt52.ru/userfiles/file/fipivezoki.pdfIn PDF document text
    • https://imagebeaute.fr/userfiles/file/naladogituf.pdfIn PDF document text
    • http://geometramaurotozzi.it/userfiles/files/43627212603.pdfIn PDF document text
    • https://micsys.in/userfiles/file/71475360238.pdfIn PDF document text
    • http://analogsys.com/uploaded/file/11530668260ed916f5303c.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/tokurerutufukewoz.pdfIn PDF document text
    • http://gamecoast.by/uploads/files/80219217804.pdfIn PDF document text
    • https://festivaldelmaridaje.com/sgi_userfiles/userfiles/files/tuselikizunexatijatidedek.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160719d5c872c6---8707232263.pdfIn PDF document text
    • https://efnnma.org/files/file/75370622243.pdfIn PDF document text
    • https://joebalogh.ro/imagini_ws/83893355967.pdfIn PDF document text
    • http://business-plan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/fusigemoreja.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a75494eabe3---febegozupebojapifokemexa.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/873655c8d0704ffa9e86891843afa846/ditul.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/neponulewi.pdfIn PDF document text
    • http://yuhongzg.com/d/files/rajuwoxafebegog.pdfIn PDF document text
    • http://perila-vrn.ru/userfiles/file/20988714606.pdfIn PDF document text
    • http://ebiocell.com/uploadfile/file///2021052014334020.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d84b65470f---sowoboxivab.pdfIn PDF document text
    • https://poolpoint.be/uploads/file/zowizaxa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=terminologia+genetica+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://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_off0000e0eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0EB 10756 bytes
SHA-256: b7ca21dbc74c37170c768d6afd0e452473ffaff78256660431dba70ac3fb2ce8
font_01_sfnt_off0000f967.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF967 17900 bytes
SHA-256: 2f872dc795db6c9cefe061d523f350d141384eebda77efe6b4a020685e1b81f2
font_02_sfnt_off00012816.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12816 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1