Malicious PDF — malware analysis report

Static analysis result for SHA-256 a578b4d4e1dad310…

MALICIOUS

PDF

79.0 KB Created: 2021-09-13 09:46:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ee777a86b70228d309f17888359df35e SHA-1: a6498f833021c07b624b6787e886188b76a2d053 SHA-256: a578b4d4e1dad310f4ed08e37171eeacd968e1b34e3ed36a90761fc4a6b53305
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external websites, many hosted on disposable domains or compromised WordPress installations, indicating a link farm designed for malicious redirection. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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://chcial.ru/uplcv?utm_term=funtouch+os+android+11 PDF link annotation
    • http://xiangzhuan.tw/upload/files/34346164261.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/v7tvg4kqti1bc4f101f92icpul/fapuramitokigofu.pdfIn PDF document text
    • https://zaindu.drogomedia.com/files/galeria/files/wezopinexagepagoziba.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613244f0cfcb2---87072872147.pdfIn PDF document text
    • https://grupahatak.pl/admin/_fck_files/file/18803662497.pdfIn PDF document text
    • https://sibois.eu/userfiles/file/xavekatazukosu.pdfIn PDF document text
    • http://tehla.eu/userfiles/file/gideni.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16136cc80f1fc0---56838453159.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/dexaxid.pdfIn PDF document text
    • http://aolisenjiancai.com/data/files/83656010455.pdfIn PDF document text
    • http://snieznik.pl/userfiles/file/79571670644.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133f984e31fc---14942332221.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/51104052515.pdfIn PDF document text
    • http://pilanatofishing.com/home/sandbox/domains/shelter.sandbox.tritek.hk/public_html/ckfinder/userfiles/files/62693334058.pdfIn PDF document text
    • http://latiendasegura.com/contable_prueba/userfiles/file/feziximem.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab2c7baa06---rilisuvuvasojexefejitu.pdfIn PDF document text
    • http://ky-auto.com/uploadfile/files/14882936516.pdfIn PDF document text
    • https://questyme.ca/userfiles/file/bukamowojonaxom.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/lekezuf.pdfIn PDF document text
    • http://computergramm.com/userfiles/file/83913652907.pdfIn PDF document text
    • http://mfcpavpos.ru/file/57943365242.pdfIn PDF document text
    • http://dailygameresult.com/editor/UserFiles2/files/6117427207.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/retuzetudidavawewewe.pdfIn 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://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_off0000c851.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC851 21140 bytes
SHA-256: eda8e12d018229193cad1df35ec6ecb520a5359fdb5742d48f50b63f4b776c9e
font_01_sfnt_off0000ff73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF73 10416 bytes
SHA-256: 5c0103ca8915e412c2e395e6f748cfd865491c2492cc3a00a0ba43562a6125da
font_02_sfnt_off00011707.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11707 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1