Malicious PDF — malware analysis report

Static analysis result for SHA-256 91718f7bcfb580cb…

MALICIOUS

PDF

84.7 KB Created: 2021-09-21 09:07:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 76241e51cd9a2590b3a6f9b3ccc17096 SHA-1: b0de7ad88767ecabb51ef9473e29aa4565c90034 SHA-256: 91718f7bcfb580cba0315a3afe3cc198f55546344b998e6be169ac16f20913da
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs that form a link farm, with several pointing to compromised CMS uploads or disposable hosting, suggesting an attempt to distribute malicious content or phish users. No scripts were extracted, but the presence of multiple external links and the overall detection profile strongly suggest a malicious intent to redirect users.

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://chcial.ru/uplcv?utm_term=how+to+make+your+own+android+phone PDF link annotation
    • http://space-edge.com/upload/files/fodisiw.pdfIn PDF document text
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/3369738598.pdfIn PDF document text
    • http://ji-tien.com/userfiles/file/40598025240.pdfIn PDF document text
    • https://www.utn.ac.cr/sites/default/files/files/13631326533.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614200e041e18---57160063048.pdfIn PDF document text
    • https://cosanuesa.com/componentes/editor/ckfinder/userfiles/files/wowelavuviboza.pdfIn PDF document text
    • http://appartementslisa.it/an3_Uploads/file/44893841142.pdfIn PDF document text
    • http://cnokorea.com/userfiles/file/pozodubinadal.pdfIn PDF document text
    • http://biurod9.pl/public/userfiles/file/10783183277.pdfIn PDF document text
    • http://platypusspot.org/uploads/ckfinder/userfiles/files/61952677303.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161468f300535a---vosupexajavezegi.pdfIn PDF document text
    • http://perfekt-dom.pl/designhome/admin/userfiles/file/43995616208.pdfIn PDF document text
    • http://e2ingenieros.com/ckfinder/userfiles/files/denanuwokubovipi.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/16130c9fadd25b---waxubesemipibax.pdfIn PDF document text
    • https://paradigma.bg/uf/file/kaluwokawalaxuxarep.pdfIn PDF document text
    • http://sysquare.com/UserFiles/files/jalewavifusabowebamabuz.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/a31b9b99b11d8ddbaf2e483d1ee05b65/losume.pdfIn PDF document text
    • http://www.synagoge-stommeln.de/ckfinder/userfiles/files/bumobafejovesopovabami.pdfIn PDF document text
    • http://jikaramen.com/uploads/files/rigotifusow.pdfIn PDF document text
    • http://sakem.org/userfiles/files/51832121258.pdfIn PDF document text
    • https://etevent.itweald.com/uploads/files/613867c8a9938.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_off0000e627.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE627 10828 bytes
SHA-256: a582c932b389c18b18e6867f200b5b9ba55e0aa20b68a69ee3db1b49d9465b41
font_01_sfnt_off0000fee9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEE9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000116fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116FB 17620 bytes
SHA-256: ac86eb846a28ca47f317ae61c8b22e4fdc709f7f8a96d7fa4a281e28021de4de