Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3d7146e36609c23…

MALICIOUS

PDF

85.5 KB Created: 2021-06-25 14:57:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c5707507347b6616f5dc8299f0b18197 SHA-1: 94b0c6400646da9f452c637714ac57df0fe9b816 SHA-256: c3d7146e36609c23503c1a829f337195c83dba2b793ba381c88bfd8015dd9e82
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to multiple compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of external URIs and compromised CMS upload links are key indicators of this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608a8c3498ceb---28422881707.pdf In PDF document text
    • https://cmsschoolkg.org/userfiles/file/44923532732.pdfIn PDF document text
    • https://gamasteel.net/userfiles/file/94811327108.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/35027895485.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160926fd422047---41766518442.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/9d9e25cce6a41802ea5ab68e4c8e1cad/debexufupugowu.pdfIn PDF document text
    • http://sl1971.com/clients/5/51/517263f0417f9379c67e6eba0e0bdfe8/File/96332228886.pdfIn PDF document text
    • https://gregor-biffiger.ch/userfiles/file/zeritidabiz.pdfIn PDF document text
    • https://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/36133792485.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b519a294c7a---90913179380.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/kfo01l6e28483r0ju4jl9l55hn/35736115077.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608056771c36a---wamutato.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/gapotonemog.pdfIn PDF document text
    • http://teplolux72.ru/upload/file/sapibiminubifam.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/jn69aqb8bfgee338g2onf46tqr/fowidedoranirejuxulo.pdfIn PDF document text
    • http://5m-tti.com/uploads/image/files/turolubezorazujaxanovi.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160841f36c0bfd---xenunetej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+draw+supergirl+easyPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d464.bin
a90b4370364c8ad49c5045c88c14bc0fded5b4a8c7d125b6f3a505e63103d72e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD464 16464 bytes
font_01_sfnt_off0000eb30.bin
32b233c7b67d516777ddc8960cee4c174c75648c1e8df2860d935834ca29f4d3
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB30 10752 bytes
font_02_sfnt_off000103db.bin
20fac3e85b422a2d148c9e5bbb798a5ab28cd041c2f4e4fbdaaafc8bce506f48
pdf-font-stream PDF embedded font (sfnt) at offset 0x103DB 17124 bytes
font_03_sfnt_off000130b4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x130B4 16792 bytes