Malicious PDF — malware analysis report

Static analysis result for SHA-256 8734ac2420154fdb…

MALICIOUS

PDF

77.8 KB Created: 2021-03-23 02:49:58 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 90ab3ac87e8f9dd6671368f2a08dcfa2 SHA-1: e00a11e8bd7a1b7da6c9fa5ca245c8dc7a6c3ca7 SHA-256: 8734ac2420154fdb9511ceeabce27182a77acf48953ec855a6a3c43a1fcb8e1b
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm used for phishing or malware distribution. The document body, though heavily obfuscated, appears to be related to educational content, likely a lure to disguise the malicious nature of the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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
  • 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.
  • 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://jacksth.ru/123?utm_term=factorising+ks4+worksheet PDF link annotation
    • http://iclod.tech/warhammer_40k_rulebook_free7iuyf.pdfIn PDF document text
    • http://sunufosabupes.scienceontheweb.net/21363984146.pdfIn PDF document text
    • https://norajaxufok.weebly.com/uploads/1/3/4/6/134611117/girelajapekup_fujaxozados_lavowejozisujan.pdfIn PDF document text
    • http://replyua.site/polojekodufogafupupu16m7t.pdfIn PDF document text
    • http://nely.xyz/guwudaxatubukevigikuxurnkiq5.pdfIn PDF document text
    • https://vozozexofevufut.weebly.com/uploads/1/3/1/8/131871902/zadegovuxotuderosur.pdfIn PDF document text
    • http://drnextact.xyz/401507711312x7js.pdfIn PDF document text
    • https://nizakibete.weebly.com/uploads/1/3/4/3/134386075/7083764.pdfIn PDF document text
    • http://requiremcgood.com/82295098984jcng1.pdfIn PDF document text
    • http://gapilojazixo.getenjoyment.net/waladuxigoped.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://15319a82-8c66-4906-b3c2-464277991f2b.filesusr.com/ugd/070acf_6db971942213401588d56252b694faab.pdf?index=trueIn PDF document text
    • http://nofolimuri.myartsonline.com/english_literary_devices.pdfIn PDF document text
    • http://pusebirenox.myartsonline.com/5601040069.pdfIn PDF document text
    • https://8d2868a3-57b7-484c-81f6-493c1c4f5daa.filesusr.com/ugd/a8ca0f_02e1206892d04ce98bddf97336ea3f4a.pdf?index=trueIn PDF document text
    • https://45ae50e1-98a8-4501-9ad6-fc0df438eb43.filesusr.com/ugd/b16523_67c2d05872c2401fb95d055058fb66cd.pdf?index=trueIn PDF document text
    • https://99470c7d-c692-4648-a7b8-36ea19db2883.filesusr.com/ugd/ab059d_b904f400a67449d9ba79f7e29704122e.pdf?index=trueIn PDF document text
    • http://buvizukiwixo.rf.gd/battle._net_fr_mac.pdfIn PDF document text
    • http://siginexexurop.epizy.com/article_rewriter_tool.pdfIn PDF document text
    • http://mowosafawun.rf.gd/vidujijepowesezenepaj.pdfIn PDF document text
    • https://c6f55193-7475-4343-97dd-33cb3b141b6a.filesusr.com/ugd/808d8c_dc9858f197c4487384b527458fd735c3.pdf?index=trueIn PDF document text
    • https://7b4e975e-109f-4397-a679-93e438ff1453.filesusr.com/ugd/c33f71_dd29b64c095444d8a42e292240c3189e.pdf?index=trueIn PDF document text
    • https://128fc002-9ed4-4a8f-9a6b-83b43563a9ed.filesusr.com/ugd/6812d7_8073f3a0e5e2445f9638bb6b4db52cbd.pdf?index=trueIn PDF document text
    • http://fukorow.epizy.com/wuwidab.pdfIn PDF document text
    • https://b3a1a1c9-4f8f-4fb8-b7cc-7339030cc889.filesusr.com/ugd/162fe6_d2bc34a587af413eb2269813084c1543.pdf?index=trueIn PDF document text
    • http://gukofeverozek.rf.gd/basic_electronics_questions.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_off0000f1a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1A7 5228 bytes
SHA-256: e16f4959112f413ad8eeb4ea676bc6b07299e255cdafceb2b6c9eb0e3df33e53
font_01_sfnt_off0001038a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1038A 11256 bytes
SHA-256: 68d1c5d91ebcd78dfe87666d2b00afe95e2ca6c62c4821409c8dc90dc6155c4a