Malicious PDF — malware analysis report

Static analysis result for SHA-256 b72a5f3255a26713…

MALICIOUS

PDF

79.9 KB Created: 2021-09-17 22:07:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 56009a07bd90a86836682fcd853af1ce SHA-1: 965f8c6ef7426895156ca7676c2eec75d4366c1c SHA-256: b72a5f3255a267132da1909998b976f1ae984023fdb32cc8fc27c87620397512
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external sites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://enilubricant.hoakhanh.vn/uploads/image/files/jumixomuwomalugupa.pdf In PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/jodusibebujijomuka.pdfIn PDF document text
    • http://373113.linker.tw/files/juzidomizatusoxoliti.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/c2f38eba659e800680e80b6fd407d86b/xakarosimat.pdfIn PDF document text
    • http://bancasemecanino.com/userfiles/files/renozora.pdfIn PDF document text
    • http://izmirtavla.com/upload/file/56611789890.pdfIn PDF document text
    • http://twfbs.com/ckfinder/userfiles/files/zabamowisodugas.pdfIn PDF document text
    • https://lidiyageorgieva.com/ckfinder/userfiles/files/kejesopefibinabatune.pdfIn PDF document text
    • https://aalatour.com/basefile/b2caalatourcom/files/gefowefajorozez.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/5374909013.pdfIn PDF document text
    • http://2015.letnifestiwal.pl/ckfinder/userfiles/files/nukitivilanubuzunidus.pdfIn PDF document text
    • http://vecsecity.info/editor_up/8909509206.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/161432eab15c49---87744515779.pdfIn PDF document text
    • http://aow.infogestnet.it/ckfinder/userfiles/files/45804737869.pdfIn PDF document text
    • https://shipnhanh247.vn/asset/files/dukufisakelubu.pdfIn PDF document text
    • http://krr-nfe.com/suratnfe/UserFiles/File/45162084639.pdfIn PDF document text
    • http://ukicda.com/admin/fckeditor_upfiles/file/2021091223530580554.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614381cf89150---pewulomabesifoduz.pdfIn PDF document text
    • http://launensia.cz/ckfinder/userfiles/files/8820440036.pdfIn PDF document text
    • https://onecre.com/images/content/files/30986642205.pdfIn PDF document text
    • http://zaiger.ru/img/file/fokuxukefizebup.pdfIn PDF document text
    • http://fabtur.ru/upload/files/39816480799.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=how+to+get+free+boost+discordPDF 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_off0000d5c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5C0 16944 bytes
SHA-256: 410085c4561300fe134abec3f53f1d54f9d4f9ff889bc3ec574ce0cb8e5cdb02
font_01_sfnt_off000101c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101C9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119E0 10556 bytes
SHA-256: 0da012ad9807e037435b0a5065365e7d1a3c55b23b07ff2837cd281a53848b6d