Malicious PDF — malware analysis report

Static analysis result for SHA-256 8291bfa4311e1c01…

MALICIOUS

PDF

85.1 KB Created: 2021-09-16 15:55:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 21a071515060cdd79f41e59fb6d645be SHA-1: ee19b34b1c0be15dc26cf0522124ef52caa05cf8 SHA-256: 8291bfa4311e1c01c950500b27fa2c18507c1ca156a4da3c0cf17da27d03bb23
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 high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to distribute or mask malicious content. The presence of multiple external URI heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://schokofontaenen.de/idata/13064430986.pdf In PDF document text
    • http://chinhsuasolieu.com/media/files/rexipunim.pdfIn PDF document text
    • http://naturpix.ch/cmsimages/file/bamegumopufekamukifusow.pdfIn PDF document text
    • http://areawifi.com/DESARROLLO/userfiles/files/38486591854.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/6pkul1ht25konaqd66mgmet8p6/tuwigigovot.pdfIn PDF document text
    • https://www.whoamiandwhyamihere.com/ckfinder/userfiles/files/tapirek.pdfIn PDF document text
    • https://activepymes.com/pub/file/dolotiwe.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/kijijibufezuxa.pdfIn PDF document text
    • https://impulsa.mantareys.net/uploads/plantillas/files/velatugofunigizawopuvopu.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/muvolorewofalowewo.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/14811482046.pdfIn PDF document text
    • http://sanfrancescovet.com/userfiles/files/dodekowuxazolex.pdfIn PDF document text
    • https://appchecar.com/ckfinder/userfiles/files/fidudanoserigiletoxebuxef.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/uf8t19p72m6edsmkp6gmh8ju8h/81635685224.pdfIn PDF document text
    • https://detectiveoffice.net/userfiles/file/sewegotujavuruwejabed.pdfIn PDF document text
    • http://omatsuri.kr/data/userfiles/files/97338971497.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/vejobivovobenusaful.pdfIn PDF document text
    • https://nbc.com.vn/ckfinder/userfiles/files/nelexiwafapavitefepumob.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ce3635972c---moburepivev.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/36167800198.pdfIn PDF document text
    • http://stlnsk.ru/uploads/file/53290491410.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161342703a1604---46619369323.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=gta+vice+city+free+download+apk+and+obbPDF 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_off0000e6ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6AE 10984 bytes
SHA-256: cce88a1fc40de7e74e28ae6009d8e762775343dbc4e4cfba97879abd7aa88f3e
font_01_sfnt_off00010028.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10028 18080 bytes
SHA-256: f9bacda86f16c4ce47f32aa6806f4b8da958c4b77091173accaa0beb3e3f3455
font_02_sfnt_off00012eae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EAE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1