Malicious PDF — malware analysis report

Static analysis result for SHA-256 164cefbbba2c21aa…

MALICIOUS

PDF

83.8 KB Created: 2021-09-21 01:14:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7c7261131caed8c823e88029035e442a SHA-1: 325fda7519db07d7741e5f2661dbaa9d70dd6e88 SHA-256: 164cefbbba2c21aaed5f96b7d0609970f421d1ee9b853c9e0dda61d2d7c00c52
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as containing a link farm and was classified as malicious by an ML model and ClamAV. The embedded URLs, particularly the one hosted on 'bagandpack.ru', suggest a phishing or malware distribution attempt. Although no scripts were directly extracted, the nature of the link farm indicates an attempt to lure users to external resources, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://milliondollardesiclub.com/upload_files/featured/files/96347734812.pdf In PDF document text
    • http://colafranceschi.it/userfiles/files/vogidurefiki.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/gipijivukoxowasibulota.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/miwanerijenotupak.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/faxivos.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/a4ad5b11dc69e65a0a11d99c4e4eb6e1/rajirifemota.pdfIn PDF document text
    • https://baatco.com/ckfinder/userfiles/files/12135099090.pdfIn PDF document text
    • https://artgallery.devctn.com/ckfinder/userfiles/files/7170711000.pdfIn PDF document text
    • http://martonaroniskola.net/userfiles/file/wegivu.pdfIn PDF document text
    • http://abnig.friendship-match.com/upload/files/10406301266.pdfIn PDF document text
    • http://k12kos.com/ckfinder/userfiles/files/wibirigadakokegobawik.pdfIn PDF document text
    • http://turinhotelcompany.com/userfiles/files/sejekarugo.pdfIn PDF document text
    • https://nexapos.com/upload/files/nekixesamivigujawajaku.pdfIn PDF document text
    • http://tomdythai.com/userfiles/files/najibesuzumutotutivejo.pdfIn PDF document text
    • http://fluorescent-training.com/file/27955041819.pdfIn PDF document text
    • http://machin.kr/userData/board/file/33319727192.pdfIn PDF document text
    • https://umutisi.com/umut/upload/files/31385468782.pdfIn PDF document text
    • http://goldcoil.com/uploadfiles/files/bokukexowuvirilepeguzopam.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/d945bdde9bdffb9003df08607abc9e32/84385943234.pdfIn PDF document text
    • http://win-sonic.com/ck_imgs/files/74886048353.pdfIn PDF document text
    • http://sieuthibds.net/images/files/40003520465.pdfIn PDF document text
    • http://lisaarkin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/47353100910.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/35b6fbe29989877049b1be5cd5a10819/lupisa.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/23bc7b577c58b4ff6aa55b5aa2981754/xosibetiregisomosi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=bluetooth+hartslagmeter+androidPDF 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_off0000e213.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE213 17848 bytes
SHA-256: b2b43979deac61c8f406f6c9b465150083edf0e59fae3286c1d0e8564bff82b0
font_01_sfnt_off00011045.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11045 10848 bytes
SHA-256: 4bdaf09158be07df7a847361bb9bdad484af7b538e9f3ab08a9b9605ce146fdb
font_02_sfnt_off000128ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1