Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f53b9df9d4e2b1a…

MALICIOUS

PDF

88.8 KB Created: 2021-07-03 01:30:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 67a6f024e24e829ed686ec5baea43fa2 SHA-1: f6a2df4bbc8bd9b07a723360ea974d0b4fa9b648 SHA-256: 3f53b9df9d4e2b1a28bbb38c31b207f453f20d6527e8df6d1e04a4756e54f32c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm with numerous URLs pointing to compromised WordPress sites and disposable domains, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV also flagged this PDF as malicious, suggesting it is used to lure users to malicious content, likely for phishing or malware delivery. The presence of multiple unknown and potentially compromised URLs makes this a high-risk artifact.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16097fd553c86e---pujudopixakapoti.pdf In PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160b47adbe9ebb---vozalufexobute.pdfIn PDF document text
    • http://aite-materials.com/upfiles/file/keludofoxumamixewasugaf.pdfIn PDF document text
    • http://trungtinjsc.vn/upload/FCK/file/44809871367.pdfIn PDF document text
    • http://ledson.ru/upload_picture/jogevoxirodatigem.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/9901898899.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/af3cc8c8004c21bd1cbd689d450eb6a0/45088182299.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9acbc676d8---vefagupox.pdfIn PDF document text
    • https://taevlingar.se/images/pages/file/3725286491.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a1a20d8d23f---woralafanibofigakenuner.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/lj8bf1hkiqej2mj9na5rguejeq/fuwowuko.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/16074662099d60---80117060210.pdfIn PDF document text
    • https://chung-pei.com/userfiles/file/7522605777.pdfIn PDF document text
    • https://anukulagrotech.com/userfiles/file/96491284209.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/kupakikigoxojijasusamup.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d500c68bbd---21544630925.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a9307d63bbf---3830258067.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8872927766---41549620975.pdfIn PDF document text
    • https://scanclean.bg/upload/ckfinder/files/98784283188.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/33fc40a32694ec58785920084b168ac7/wiwupunomonamileta.pdfIn PDF document text
    • http://hcviet.com/img-phuctri/files/26607220594.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/qbp7mgoufaekurcak8pjeshku8/dosiped.pdfIn PDF document text
    • http://podlahypilat.cz/admin/file/fezem.pdfIn PDF document text
    • https://ghnservizi.com/file/wapek.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/16070785ddd06d---pivene.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=candy+crush+soda+apk+downloadPDF 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_off0000f93b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF93B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001114d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1114D 16936 bytes
SHA-256: f8dd93235163e7b45da2bf6137eafca4bb50b05956a7465db4ad0e8459f300e8
font_02_sfnt_off00013d89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D89 10712 bytes
SHA-256: dc9f7b69d8b1da8a5d3f058598cb3ae4b13fe2041dadf291787629698df7aa8a