Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ccb734c33323899…

MALICIOUS

PDF

74.6 KB Created: 2021-09-01 20:06:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8bcd315d67e61b81be537558524198dc SHA-1: 47de96c3c085c3c015cc8053914fe1a35d90f210 SHA-256: 4ccb734c33323899361150c33b63ebf1965dff7f2775f78db8955265e71d8aca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Several extracted URLs point to compromised CMS upload directories, suggesting a potential phishing or malware distribution scheme. The PDF structure itself appears to be a collection of links rather than user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://akkoryazilim.com/userfiles/file/90947387595.pdf In PDF document text
    • http://letresorellebio.it/userfiles/files/rovevokakijorufamudoge.pdfIn PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/jufidig.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad052526d96---93404710981.pdfIn PDF document text
    • http://brlairport.com/images/file/dufotirikof.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b9836e51eec---95388396657.pdfIn PDF document text
    • http://bjzjygj.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/nipoleretasew.pdfIn PDF document text
    • https://burkina-businessschool.com/business_school/uploads/file/wosigezixepexakunipam.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b7efa16e07b---tipolozorezowad.pdfIn PDF document text
    • https://ipssecurityconsultants.com/ckfinder/userfiles/files/76270338418.pdfIn PDF document text
    • https://www.gryf-wet.pl/ckfinder/userfiles/files/44829075079.pdfIn PDF document text
    • http://speednewslive24.com/assets/ckfinder/core/connector/php/uploads/files/lafuxurunuxubigep.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d403797b7a---tixojonodowidarid.pdfIn PDF document text
    • https://paperland.bg/uploads/file/56453436410.pdfIn PDF document text
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/72f956659ec79587feaa570ac88687c5/41363244094.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/80400725926.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160f89f3216ff9---toverapusazo.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/33f3c1u0tihko7lo9ua4d5mnp0/53865461539.pdfIn PDF document text
    • http://sonsuadogo.org/Images_upload/files/kigesejijenadelo.pdfIn PDF document text
    • https://beldapin.com/calisma2/files/uploads/78354256346.pdfIn PDF document text
    • http://fabriziocar.it/userfiles/files/xoxonazetexiremojozixir.pdfIn PDF document text
    • http://tetraeng.it/userfiles/files/52941422837.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/n8ik5bfr348d0m2jdqnl2bopb2/lirivululumezijunufojixid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=best+schooling+fish+with+angelfishPDF 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_off0000c0f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0F9 16568 bytes
SHA-256: 068dea4db1b3ce9d8419ae809f82295ab69d67c2c1d95a850c6410df175b4d2d
font_01_sfnt_off0000eb46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB46 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001035d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1035D 10656 bytes
SHA-256: 0558d409ffe49548484422738f04c88dd51df156a657d9ae34800a172b26bab0