Malicious PDF — malware analysis report

Static analysis result for SHA-256 2138a475c863c7e2…

MALICIOUS

PDF

91.8 KB Created: 2021-09-16 17:42:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b836be933dbd957c4a67e6e52101c82f SHA-1: 2e2985f47d56afe8f6a39822015fbf0c50c5e706 SHA-256: 2138a475c863c7e2c6314e18957bb7aa4346baf6d822fdc06a140160f1851463
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The presence of these links suggests an attempt to lure victims to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/03d0db9e246ebdafa339b6e9b24f689d/xogugemezazagekat.pdf In PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/99960190596.pdfIn PDF document text
    • https://ht-cooling-j3t.com/contents/files/60689658641.pdfIn PDF document text
    • https://larustt.com/upload/ckfinder/files/60944858040.pdfIn PDF document text
    • https://mandarinusa.com/userfiles/file/1630696224.pdfIn PDF document text
    • http://iccjsc.vn/images/uploads/files/jexokotavax.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c98c9cf33b---99354852162.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/pozuroxowil.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614061e44675b---4684486186.pdfIn PDF document text
    • http://hophungvietnam.com/app/webroot/uploads/files/pesopi.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130959511ec5---gemerusibidirepitogutir.pdfIn PDF document text
    • https://menu2uplus.com/images/file/45002109144.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/siwijinejakakubesosumokus.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/files/19422214705.pdfIn PDF document text
    • http://defhjdrjioo.friend-match.com/upload/files/35619171176.pdfIn PDF document text
    • http://soundspace.eu/Upload/file/dakokekeliboletadefud.pdfIn PDF document text
    • http://eskuvoiiranytu.hu/blog/file/zesabamofarosivot.pdfIn PDF document text
    • https://navliecky.net/userfiles/file/fujunadukosifiganilax.pdfIn PDF document text
    • http://infiniti.e-library.tw/uploads/files/81222815076.pdfIn PDF document text
    • http://dentish.ru/ckfinder/userfiles/files/pukekajetisibes.pdfIn PDF document text
    • http://www.cpiequipos.com/assets/images/user_files/files/30276254791.pdfIn PDF document text
    • http://6nergy.fr/6nergy/sites/default/user/file/lasisijivifutilaba.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021091105195895.pdfIn PDF document text
    • http://sancheonglittletheaters.com/upload/userfiles/2021/09/files/210903190328.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=kris+marshall+doctor+whoPDF 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_off00010117.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10117 10476 bytes
SHA-256: 9be2b7ee3a464d65adf6c91c9d41f4434ed4754f1cf94dec47bced0fd1d99b2d
font_01_sfnt_off000118ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118ED 18832 bytes
SHA-256: 09dfa3b081dc66e08dd1ecbb5fe7ab6fc7cf3ae4e545180e8ebcd98e1eeaf717
font_02_sfnt_off00014988.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14988 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1