Malicious PDF — malware analysis report

Static analysis result for SHA-256 158b6c75ac62ed88…

MALICIOUS

PDF

73.5 KB Created: 2021-05-29 17:51:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: f072e95b4c93e511caa891ae60b7568f SHA-1: 8184a303c054ee1b2de75ea917449a1e580db58e SHA-256: 158b6c75ac62ed88a2dd371ca661ecc9e1edd96e4a4cd887e9130f42e4b5c278
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://irlanc.ru/uplcv?utm_term=revised+syllabus+of+class+10+cbse+2020-21+sst PDF link annotation
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/7b5d6fe14e3411e42e42e2a4e5b3e165/bujemugam.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/c1866386b4e5da8cdff828337b4e3e8c/nupuxonoverosonasok.pdfIn PDF document text
    • https://kopari.hu/files/file/35097835856.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160af978108ea2---vememo.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/m9tp3bujr2se4cl1oggdg90pt0/bifuvovedis.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607c77d471c90---buwusegusiruzizuxuzow.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160a6262eb0f87---56191689132.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/87433413ed5d8da9ad62a2a6c8544155/54832923914.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160748dcb606ed---17520183842.pdfIn PDF document text
    • https://alllegaltask.com/wp-content/plugins/super-forms/uploads/php/files/r13gn88bqb07u1qcrlik6koss4/79593772804.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/voxabawerotutewulepar.pdfIn PDF document text
    • http://notarbrazda.cz/userfiles/file/44852446268.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ebf013b63d---83506906858.pdfIn PDF document text
    • http://fouladsazanco.com/Upload/file/91735612670.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/30597dbcb7994f69e1729d464b7f9caa/78803112365.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/dc704fd4d9c224fd6d8c671728a60396/newubojamibuwabij.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e191.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE191 5584 bytes
SHA-256: 8079e13e6e132f3d7abf951ad5821ad4b6e90d2524eea086c68fa7670880d25d
font_01_sfnt_off0000f4c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4C3 10416 bytes
SHA-256: 9a461433047644d109334bd8e52094b92efe332d201aed3fccf58875d0492dbe