Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f9b16b334bc585b…

MALICIOUS

PDF

72.9 KB Created: 2021-02-23 17:06:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: 6aa3179f7bc4d701f14c1c201b007184 SHA-1: 1c955b3046852fc0793f94b461209300e0dda88f SHA-256: 3f9b16b334bc585b2e7201010861d21cbb7fabaa4d3324e18642526f59edf31f
244 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, with a critical heuristic firing indicating it's a malicious redirector link farm. The document body, though heavily obfuscated, suggests a lure related to 'kindergarten worksheet book pdf'. The presence of multiple external PDF links and a critical ClamAV detection for 'Pdf.Phishing.Trojan' strongly indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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 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.
  • 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://yafferge.ru/wb?keyword=kindergarten%20worksheet%20book%20pdf In PDF document text
    • https://static.s123-cdn-static.com/uploads/4445116/normal_60076194176ea.pdfIn PDF document text
    • http://present-mag.ru/tijekoloo27ru.pdfIn PDF document text
    • https://cdn.sqhk.co/rorezina/gUgiqih/lalelukiniripijemitu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370270/normal_5fe0eeefb95c6.pdfIn PDF document text
    • https://salexutoxor.weebly.com/uploads/1/3/4/7/134761189/b60a5a5e106.pdfIn PDF document text
    • http://silusexiva.iblogger.org/74509213717.pdfIn PDF document text
    • https://cdn.sqhk.co/zadoweferoxe/hihghhI/69528938716.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4452850/normal_5fedaa5beda5b.pdfIn PDF document text
    • https://cdn.sqhk.co/dudugetogi/dfIu4hb/my_electric_meter_has_a_blank_screen.pdfIn PDF document text
    • https://cdn.sqhk.co/rofezurit/ieQ5hi1/bubble_incredible_shooter_puzzle_apk.pdfIn PDF document text
    • https://cdn.sqhk.co/feripamapuv/zhaibia/notes_and_lists_iphone_app.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486350/normal_601c71a129d09.pdfIn PDF document text
    • https://cdn.sqhk.co/kepebeso/AhiUheZ/naronowulibibanim.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4466689/normal_5fd2252f56aee.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://zoxutuperovizo.epizy.com/lovimugube.pdfIn PDF document text
    • http://gapisamiwabu.epizy.com/ladiduluvasuned.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000de0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE0B 5536 bytes
SHA-256: 0fa4f11d384c7e0f61c59d2936e49b0aff9e261844b8860aaa2111e831307e70
font_01_sfnt_off0000f0eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0EB 11344 bytes
SHA-256: 5f21d5d5004b9c92a011662ce8a9aff82f53759181cf241af2c3ae6a3ed6ac32

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