Malicious PDF — malware analysis report

Static analysis result for SHA-256 19831f9eed1f7808…

MALICIOUS

PDF

78.7 KB Created: 2021-04-03 03:50:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: aef50cbd267a40c080309d53ce1af92b SHA-1: cf38a9b36d64f08de7428e972cb80daea12a3cfa SHA-256: 19831f9eed1f78082420eab3cce206c20a62785e917baa745150b5157912bf74
244 Risk Score

Malware Insights

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

The PDF document exhibits characteristics of a link farm, containing numerous embedded URLs pointing to various domains, including disposable hosting and known redirectors. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or SEO spam campaigns. No scripts were extracted, but the sheer volume of outbound links suggests a malicious redirection or content delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://dafemum.ru/strik?utm_term=how+do+you+cure+chilblains In PDF document text
    • https://dofuzubakav.weebly.com/uploads/1/3/1/6/131606612/waxunewiko-ritexa-sevagubuseta-tojakuraliw.pdfIn PDF document text
    • https://nedotumawu.weebly.com/uploads/1/3/4/6/134626041/1021409.pdfIn PDF document text
    • https://sazukigozozabep.weebly.com/uploads/1/3/4/3/134310948/e02ca93e3b7fa1.pdfIn PDF document text
    • https://cdn.sqhk.co/binuwaxe/Q8idXgi/gisejimaworadimosaxar.pdfIn PDF document text
    • https://cdn.sqhk.co/zojixemem/SMiaPhg/53329533777.pdfIn PDF document text
    • https://cdn.sqhk.co/tixuniwe/yhdw1hi/zombie_apocalypse_game_2018.pdfIn PDF document text
    • http://kisegojunu.22web.org/can_windwalker_monks_use_polearms.pdfIn PDF document text
    • http://gatorama.space/70382820454ddoq0.pdfIn PDF document text
    • https://cdn.sqhk.co/xewafazuk/pTeKgib/guess_movie_title_picture_quiz.pdfIn PDF document text
    • https://nasabera.weebly.com/uploads/1/3/4/4/134447265/5916747.pdfIn PDF document text
    • http://frukt.fun/6084579873496lzm.pdfIn PDF document text
    • https://tarivoda.weebly.com/uploads/1/3/4/6/134693378/9376573.pdfIn PDF document text
    • https://rofizikijomosuj.weebly.com/uploads/1/3/4/0/134012810/29b9893782a3b.pdfIn PDF document text
    • http://national-verifyteam.com/110630673167400m.pdfIn PDF document text
    • https://zeduxuvanoripi.weebly.com/uploads/1/3/0/7/130775880/veluv.pdfIn PDF document text
    • http://lnstagramverifiedsbadgesforms.com/oecd_guidelines_transfer_pricing_wikijnlfu.pdfIn PDF document text
    • https://verebabivudasa.weebly.com/uploads/1/3/4/7/134771522/5262687.pdfIn PDF document text
    • https://terowibew.weebly.com/uploads/1/3/4/3/134370771/nifenezi_bexejilunugoj_novaba.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://f8206d31-21c4-4aef-9da9-e4259ded718a.filesusr.com/ugd/c2bdac_a428c8556c934514a9f6d4cc0dd16200.pdf?index=trueIn PDF document text
    • http://vegewamofuxa.rf.gd/gosafazusewojuninoxalu.pdfIn PDF document text
    • https://4adff18d-dc39-4349-be2c-eeb12737f1cb.filesusr.com/ugd/9117e0_890924a3aac3456da6928766fb80f880.pdf?index=trueIn PDF document text
    • https://ed59cdd8-0d75-4634-8bb2-7afdb9da103e.filesusr.com/ugd/9cb112_4aad27a8e2d34d4d8483ce8b8f831613.pdf?index=trueIn PDF document text
    • https://070488ba-e3d9-4c74-834b-445551f5513c.filesusr.com/ugd/fb83f1_3e34be2080b54c5a9f83ac3c597f8ea9.pdf?index=trueIn 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_off0000f66a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF66A 5324 bytes
SHA-256: 848a5a961caa526577b5727b15e5e3ba2fdaf590796e4154a5286fd4d2d6e2d8
font_01_sfnt_off0001088d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1088D 10848 bytes
SHA-256: 2cc105e5bd9908d97bd8ff8ac4faae83fd0d62ae3f49f9bca74c069f07c664a4