Malicious PDF — malware analysis report

Static analysis result for SHA-256 854062e8fee9254b…

MALICIOUS

PDF

82.8 KB Created: 2021-09-06 17:24:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: ff9db6386cda59bdc686fcc76af34bbf SHA-1: 833a031cc777e4f4d080ae19e48dd577536aa799 SHA-256: 854062e8fee9254b137d2f6cad7f998ee6a1625c19993055bff915a56d5f4fa6
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, many of which point to compromised websites or link farms, suggesting a phishing or malware distribution scheme. The presence of embedded JavaScript indicates an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/af29e68385bc97393cff9dca0e87354d/3526605156.pdf In PDF document text
    • https://ascinfratech.com/clientprojects/trading/file/68693593575.pdfIn PDF document text
    • http://fujavietnam.com/images/Download/gubozu.pdfIn PDF document text
    • http://brilliantsolarpaneling.com/userfiles/file/43826135962.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f34dd2db06b---9048774686.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/2c8445359c0c46f4de82c8bd0908c1d2/koner.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/0u7b2rttrvs2g6m03uvsk6lu4m/tamupezu.pdfIn PDF document text
    • http://hanarotalk.com/userfiles/file///kelazavasovuted.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613213360627d---24320558761.pdfIn PDF document text
    • https://laptopserwis.com/app/webroot/media/files/2459752904.pdfIn PDF document text
    • http://yngc.ru/admin/ckfinder/userfiles/files/tikejidegototagojonesimam.pdfIn PDF document text
    • http://rockycheng.com/ckfinder/userfiles/files/lokipukekiwi.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/45016639877.pdfIn PDF document text
    • http://carbonelite.ru/file/54861265887.pdfIn PDF document text
    • http://epoch-making.jp/js/upload/files/vomepavojijowiv.pdfIn PDF document text
    • http://straub-online.ch/userfiles/files/36527009147.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210808083339.pdfIn PDF document text
    • https://tasteadmin.com/ckfinder/core/connector/php/custom/wysi_uploads/files/77725701225.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a8eb882fb7---44575915126.pdfIn PDF document text
    • https://szamitogep-szerviz-javitas.hu/ckfinder/userfiles/files/76057655174.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///makif.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160fa7b6bdece4---xalib.pdfIn PDF document text
    • https://marblo.com/app/webroot/img/files/dotenimof.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=calendrier+des+vacances+scolaires+2019+et+2020+maroc+pdfPDF 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_off0000d573.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD573 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED85 20964 bytes
SHA-256: d9e0b3433c36c60c9b8ff1356fae98ceb902301da05c8e2f845d86cb55f49c7f
font_02_sfnt_off00012238.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12238 11340 bytes
SHA-256: b6401d4e240092b9363b83c4977c26c160aec516d20333cf31b0614a54b8a46b