Malicious PDF — malware analysis report

Static analysis result for SHA-256 99a49a3e306dc0af…

MALICIOUS

PDF

72.6 KB Created: 2021-03-31 04:59:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: a11f735a8b8b6db0f2ac5bd1d1a0e46f SHA-1: c921bbd8cb7c494e5d75a60ac0d511c88f2fcf55 SHA-256: 99a49a3e306dc0af5b039eab32f38c1f6ca46272b5752b63a4cb63ec27d20a69
244 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically as a phishing trojan. It contains a large number of embedded links, many of which are hosted on disposable domains or redirector services, indicating a link farm designed to distribute malicious content. The presence of a known malicious redirector URL further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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://crophysi.ru/strik?utm_term=what+influences+our+behavior In PDF document text
    • https://cdn.sqhk.co/govazilose/0Vf0pKt/dirt_bike_racing_2020_snow_mountain_championships.pdfIn PDF document text
    • https://cdn.sqhk.co/numobelez/eBEqdha/vojam.pdfIn PDF document text
    • http://mebupevorodo.22web.org/wuvobonozubajafutevesaso.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420432/normal_602934b32b5e6.pdfIn PDF document text
    • https://cdn.sqhk.co/gopuxipo/CYgfjeq/71777187184.pdfIn PDF document text
    • https://cdn.sqhk.co/kafosine/figbIYM/89298532483.pdfIn PDF document text
    • https://vepenisa.weebly.com/uploads/1/3/4/3/134339982/2ae098.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4425759/normal_5fff56cca17ff.pdfIn PDF document text
    • https://cdn.sqhk.co/wafavalufa/FigOifM/bejuxevufe.pdfIn PDF document text
    • https://zabosete.weebly.com/uploads/1/3/1/1/131164473/14283.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410020/normal_5fd63bb36a753.pdfIn PDF document text
    • https://cdn.sqhk.co/sedazozesufu/hiRvYsI/jutusovosevari.pdfIn PDF document text
    • https://cdn.sqhk.co/xawobovuji/AhjyQS4/kasadux.pdfIn PDF document text
    • https://zapojejomelaxi.weebly.com/uploads/1/3/0/7/130775516/6337780.pdfIn PDF document text
    • http://vijulofa.22web.org/chocobo_race_guide_ffx.pdfIn PDF document text
    • https://cdn.sqhk.co/zafupusapun/atyijMK/fiji_airways_reviews_safety.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/981df832-6a8f-491c-a792-1fb0dc52653f/how_to_fix_a_gas_fireplace.pdfIn PDF document text
    • http://dovobol.epizy.com/benefits_of_information_technology_risk_management.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/20a49bdd-5ac4-4c3f-9331-83d251736604/nidugovuf.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d5c66707-864d-4b2a-97fe-adc8e678ca7b/tusalerizovodesenazutulov.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_off0000e073.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE073 5180 bytes
SHA-256: f90dd15a7ca3e32897bcda8e972e81a01993823fff86727210b1ce102bbb9585
font_01_sfnt_off0000f222.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF222 10328 bytes
SHA-256: 201c14b074c0f9904d50610bb4379fa4e6710c1112b5c80c470dfe19fe684c9b