Malicious PDF — malware analysis report

Static analysis result for SHA-256 39aa31af1bd2ae0b…

MALICIOUS

PDF

76.5 KB Created: 2021-04-03 06:22:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 31ed59ea51db5b38da6295b163e8aa8b SHA-1: 842ebf211e1f5f7a0d0f3b61d9fc88d89a7a92b0 SHA-256: 39aa31af1bd2ae0beecce015351e32e4267f8e8cc672266ca7cf342fd4887baa
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses an urgency-based lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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/wix?keyword=maytag+refrigerator+ice+maker+manual PDF link annotation
    • https://cdn.sqhk.co/libegavezu/1NnoDJl/concert_vr_360.pdfIn PDF document text
    • https://cdn.sqhk.co/tepikipo/hhMEigo/zubadilusivigusarer.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407100/normal_6038ece66cc57.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450248/normal_601af3cbea7dc.pdfIn PDF document text
    • https://cdn.sqhk.co/tifomogoketu/a6YiGgh/florius_bouwdepot_formulier.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501495/normal_5fd3954ebe3c0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4391001/normal_6006923fd97fa.pdfIn PDF document text
    • http://zhigina.ru/quantitative_techniques_for_businessygpkf.pdfIn PDF document text
    • http://motivawka.online/945660282204qih7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4490369/normal_5fee8e0a1a26a.pdfIn PDF document text
    • https://cdn.sqhk.co/govazofaj/6N4hahi/red_ball_100_game.pdfIn PDF document text
    • http://flebolog24.com/seussical_jr_actors_script70vis.pdfIn PDF document text
    • https://cdn.sqhk.co/pavujakorige/bUhiJic/jungle_fruit_splash_a_match_3_games.pdfIn PDF document text
    • http://pek-24.cc/easy_disney_piano_sheet_music41gk8.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/41d51455-42bc-49f9-a297-65498aa10aaa/long_run_total_cost_curve.pdfIn PDF document text
    • https://59bb578d-b312-442a-858b-1a1a54b18a6c.filesusr.com/ugd/c79b1c_db0dfd94a2e04c02a7a7bfe46d46ac56.pdf?index=trueIn PDF document text
    • https://3ea853e4-7f2b-4fb0-9229-b04907a1e321.filesusr.com/ugd/d94095_da257235fcce4e3190ebfdaa043783d5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/d8074ca4-a61e-48a0-ad34-d441cafa4512/dorusovufodiliwiwom.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/82b37878-ac57-4edf-8d3f-23fedfbcf447/zedojitezijuliwuwotose.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a12408c-bfed-4a1b-868b-bc09e2cd2863/jirukugetex.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/69e90de9-b7ed-4dd8-bdf6-78cfe3e1b004/87134749270.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_off0000ef18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF18 5192 bytes
SHA-256: bb91db11351c58797cab9d75c4d3b1830d4f3fdfc7d936c0105109e6919e2f08
font_01_sfnt_off000100cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100CC 10488 bytes
SHA-256: bec8d82483c7465f2276766c86780f566d5230292d84f9b0e81d0e5697d40c15