Malicious PDF — malware analysis report

Static analysis result for SHA-256 428c3033b1b4e43a…

MALICIOUS

PDF

80.4 KB Created: 2021-04-03 21:35:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 1665325eae6b1b2af8b9456404586756 SHA-1: eea0063aee311f7199535ac8a9f5db1a4233fef2 SHA-256: 428c3033b1b4e43a7ee37e9bca19d7e18fd10c1295ed04db85c9230cb3b1f604
126 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating it is likely a phishing or trojan delivery mechanism. The document body, though heavily obfuscated, contains references to 'Split type air conditioning system pdf' and metadata from wkhtmltopdf, suggesting a lure to disguise malicious content. The presence of numerous external URIs, many pointing to disposable or unknown-reputation domains, strongly suggests these are used to host or redirect to malicious payloads, aligning with T1566.001 (Spearphishing Attachment) and potentially T1059.007 (JavaScript) if embedded scripts are present and active.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • 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 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://pelibifir.ru/award?keyword=split+type+air+conditioning+system+pdf PDF link annotation
    • http://coolmag.biz/kalia_yojana_odisha_list_20185zchk.pdfIn PDF document text
    • https://menolalosixoj.weebly.com/uploads/1/3/4/7/134714047/nupuwapakafifaxivi.pdfIn PDF document text
    • http://raifaisentapp.online/zilujarafajototordvtwm.pdfIn PDF document text
    • https://dirifulezidume.weebly.com/uploads/1/3/2/7/132740871/57302f11d12de.pdfIn PDF document text
    • http://opt15.ru/barn_burning_summaryzibsu.pdfIn PDF document text
    • http://presalle.xyz/jegewupafuxagonalisizxu5q.pdfIn PDF document text
    • http://websporizle4.com/chopin_nocturne_c_sharp_minorzja6v.pdfIn PDF document text
    • http://indir-kazan.com/ec8552_computer_architecture_and_organization_notes9zm5x.pdfIn PDF document text
    • https://cdn.sqhk.co/xojurolaruk/c9sgjjb/88002544877.pdfIn PDF document text
    • https://nogekapufininut.weebly.com/uploads/1/3/3/9/133997605/776b5a01431b4.pdfIn PDF document text
    • http://ipai.online/public_relations_officer_duties_in_school9oy6k.pdfIn PDF document text
    • http://fenellalucynelle.info/xetefalomufad247yp.pdfIn PDF document text
    • http://prosucre.pro/denon_receiver_turns_off_and_flashes_redxya8w.pdfIn PDF document text
    • https://cdn.sqhk.co/pigevikuwi/diex1Ns/download_anime_battle_of_the_cosmos_mod.pdfIn PDF document text
    • https://bojomuse.weebly.com/uploads/1/3/4/4/134462584/gokewolap-regezenut-tovatamolexi.pdfIn PDF document text
    • https://pamukisap.weebly.com/uploads/1/3/4/7/134761215/4842049.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://dujikiwereka.epizy.com/tawokivusufavikazu.pdfIn PDF document text
    • http://zixoridepub.rf.gd/sunotozitetarosi.pdfIn PDF document text
    • http://danobefaxejo.rf.gd/3d_max_tutorial_in_tamil.pdfIn PDF document text
    • https://s3.amazonaws.com/lemerisinivum/gedafazujasolale.pdfIn PDF document text
    • http://zitovidenelanus.rf.gd/34960199338.pdfIn PDF document text
    • http://sakonolib.rf.gd/basic_electronics_short_notes.pdfIn PDF document text
    • https://s3.amazonaws.com/jivagajamav/straight_talk_mobile_hotspot_device_not_working.pdfIn PDF document text
    • https://s3.amazonaws.com/wupagivoz/pakedepijitij.pdfIn PDF document text
    • https://s3.amazonaws.com/silubebebefuju/yale_emergency_medicine_residency_salary.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF14 5468 bytes
SHA-256: e16f0d125a02f5a46cda3c8083b27159e3593d84c9928f15df2904f0d0350dea
font_01_sfnt_off00010192.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10192 10540 bytes
SHA-256: c8871c6bcb667b22d6e0145888bce05ed10638d666a1dd6e852efc0b1ae775df
font_02_sfnt_off000125a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125A6 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3