Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a3eda86d4de2b45…

MALICIOUS

PDF

68.6 KB Created: 2021-02-17 13:48:07 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 306ad3981bac446921f14ea0c72373e0 SHA-1: f3c7f7b195ec15f54149f45bf5804d6a26250864 SHA-256: 3a3eda86d4de2b45171fd1de9141a1fe30a8431791dacd8f9cfb3ba340e61684
284 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to disposable hosting services and redirectors, indicating a link farm designed to manipulate search engine results or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the presence of numerous external links and the PDF structure itself are indicative of a malicious document, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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.
  • 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://crophysi.ru/123?utm_term=how+to+put+nose+trimmer+on+philips+norelco In PDF document text
    • https://cdn.sqhk.co/bunewonu/hghed9A/block_breaker_deluxe_3_jar_240x320.pdfIn PDF document text
    • https://disadaniti.weebly.com/uploads/1/3/4/4/134463451/gapedikeravarovimuta.pdfIn PDF document text
    • https://cdn.sqhk.co/lupobikud/iijErNH/machine_gun_preacher_full_movie_online.pdfIn PDF document text
    • https://xuvajova.weebly.com/uploads/1/3/1/3/131380845/3135158.pdfIn PDF document text
    • https://binoxumo.weebly.com/uploads/1/3/1/4/131452823/2868670.pdfIn PDF document text
    • http://ketrovk.xyz/vuleguvizukuzipifaseozpg.pdfIn PDF document text
    • https://zetojaxonafavop.weebly.com/uploads/1/3/5/3/135309172/pixivefox.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483335/normal_5fd8cc53d95fb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470040/normal_602a4c2fea348.pdfIn PDF document text
    • http://vinograd.io/the_art_of_the_start_guy_kawasaki_pd2ozji.pdfIn PDF document text
    • https://cdn.sqhk.co/jufebarur/eijfHgi/nature_sounds_birdsong.pdfIn PDF document text
    • http://helpcenterbusiness.xyz/62199800445yoikj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379722/normal_5fd104ef8a615.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402289/normal_6025001a28e74.pdfIn PDF document text
    • https://cdn.sqhk.co/lojosexotak/gcmdgio/9765783563.pdfIn PDF document text
    • https://banafazag.weebly.com/uploads/1/3/4/3/134325205/202158.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_off0000ced0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCED0 5016 bytes
SHA-256: 1d326d5844fa0daa94990747a321946d9b749a8fb06407281db151016d4a5e86
font_01_sfnt_off0000dfcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFCC 11064 bytes
SHA-256: 31722edc9718ccf4a97265127455efb9dedc8814f5f0909c2b58ea046d9d360a