Malicious PDF — malware analysis report

Static analysis result for SHA-256 37b8b88c3aac520a…

MALICIOUS

PDF

77.9 KB Created: 2021-05-16 09:42:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: a3f383702044e892b6ae145f5af43bf8 SHA-1: b0bfd62237e049799a6be55eb37e8daeea16975f SHA-256: 37b8b88c3aac520a2653ff7315eb2cdb1aa0e1d34443ea01b8700c3e6bd8a31f
186 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, many pointing to disposable domains, indicating a link farm or phishing operation. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious activity, likely related to spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • 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://gimoguvi.ru/strik?utm_term=lg+g2+f320l+screen+replacement PDF link annotation
    • https://cdn.sqhk.co/modonasuje/hdjbmjg/slime_maker_game_poki.pdfIn PDF document text
    • https://cdn.sqhk.co/rodesedaded/gfSr7h8/14449369505.pdfIn PDF document text
    • https://cdn.sqhk.co/fiwujumejuf/hiJe9Mg/teacher_appreciation_week_2019_ideas.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480758/normal_5fe8e87cc8132.pdfIn PDF document text
    • https://cdn.sqhk.co/rerunagakiz/ihgd4R0/vedawu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411921/normal_6036142d0a339.pdfIn PDF document text
    • https://cdn.sqhk.co/gizoxemovefi/jchajap/ravens_covid_source.pdfIn PDF document text
    • https://cdn.sqhk.co/foradimotiri/icgiFCb/bass_booster_pro_volume_amplified.pdfIn PDF document text
    • https://cdn.sqhk.co/samigimas/U4qgUgf/3d_tennis_game_download_for_pc.pdfIn PDF document text
    • https://cdn.sqhk.co/noneniwetav/agjgibL/kiku_menu_fayetteville_ga.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4381980/normal_6002b4ef38bb2.pdfIn PDF document text
    • https://cdn.sqhk.co/tosuwukiwate/rOhd2KG/bunorisirebug.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450355/normal_6046dd6cacebb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488141/normal_602e3652dafae.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/xakajoziwibi/7777717791.pdfIn PDF document text
    • https://s3.amazonaws.com/kovilowab/tubekuzataripurosupiva.pdfIn PDF document text
    • http://lakuxizutigevo.rf.gd/84502535109.pdfIn PDF document text
    • https://a815f367-2516-4b88-9496-eed07d5c1eb7.filesusr.com/ugd/665c20_069f96937408459f8b9bb3e36e84bc5f.pdf?index=trueIn PDF document text
    • http://rofizamomu.rf.gd/justin_bieber_friends_song_pagalworld.pdfIn PDF document text
    • https://21c505bb-01ca-4817-a549-4ed1ebba5040.filesusr.com/ugd/7d7105_e5fb23cc7467491fb1974f7e0f4a4b9f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/genedonapubefe/health_o_meter_weight_tracking_digital_scale_reviews.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_off0000f319.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF319 5716 bytes
SHA-256: a74865fb5fda387a260eb9384555e4fe8504a98f6855184398f22af3b761269f
font_01_sfnt_off0001068b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1068B 10352 bytes
SHA-256: a332dfe4682ed6efb08b4f320351d7508cdd2560ee1d3bc4e317af4570eeb74c