Malicious PDF — malware analysis report

Static analysis result for SHA-256 6439a37bddce684b…

MALICIOUS

PDF

85.4 KB Created: 2021-07-13 21:19:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: d97b54ffd740ac3db3cad4afb303ff1d SHA-1: 5f8d0df2f3834279bc7ed2d0b14bb9bf64d5502f SHA-256: 6439a37bddce684b391f684dad0a5566f3d520aa609cc1d6c31c637c6ec1383f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised WordPress upload directories and disposable hosting sites. The document body is unreadable, but the presence of numerous external links strongly suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://hanyauntuktesting.com/contents//files/82952076553.pdf In PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/bd91ad812997ccc12ecc9b7e8d8eb069/dinenebedudipavewudigat.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b17a2f2959---wixed.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/67586829445.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0cb60f389c---todidavegab.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/92507274870.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afabe1e6627---wogag.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160728e7357ee4---sidafevew.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/5bbda544ee89da4e9c5cfd4892b0e283/fuvul.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16071d12995b34---38604348379.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160933932924e5---filipasuxuxitupe.pdfIn PDF document text
    • http://yuanyoujie.vip/userfiles/file/68578723792.pdfIn PDF document text
    • http://be1971.com/clients/a/a1/a19be2fc4cf8b198b52f296748481ce5/File/68949137235.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/4h2ncber020c4i7cnde007mjf2/detimox.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160a06b0bcd513---8567746899.pdfIn PDF document text
    • http://jandenzobv.com/image_uploads/file/kolanupajob.pdfIn PDF document text
    • http://murielbellhomes.com/userfiles/files/kuwukogadelizuzem.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607b292395240---pimanuli.pdfIn PDF document text
    • http://www.buildingmalawi.com/images/uploaded/documents/5440097473.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/4crkb5ee5hu2c0lcngc7qp9tu4/82951912471.pdfIn PDF document text
    • http://maxgear.cz/webpagebuilder/ckfinder/userfiles/files/buforinapamigopuzib.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160e21ebbdaff3---84079962230.pdfIn PDF document text
    • http://haumeaonline.com/userfiles/file/20853638410.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=fundamentals+of+electrical+and+electronics+engineeringPDF 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_off0000e7a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7A2 17312 bytes
SHA-256: 0e4061a5fad1abfc337fbe8ba0663bc6c44935b4bb50f1ef26d95025c06db112
font_01_sfnt_off000114d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114D7 10896 bytes
SHA-256: c51f665b7a922a07ceeba51dafb782059bc778a63178c4c69e9d5702a473a8c5
font_02_sfnt_off00012dd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DD5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1