Malicious PDF — malware analysis report

Static analysis result for SHA-256 4118bcb70de39d20…

MALICIOUS

PDF

81.0 KB Created: 2021-06-14 09:01:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: e3e9a5ec8684164f9e3e8ecda4c7de1d SHA-1: 0540cbf74f16a2089ac4e89fafdc002527d168f5 SHA-256: 4118bcb70de39d20a50f561c28ecd5fa9bc1bcafd504b7115a4362c31ea87a23
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. ClamAV and ML classifiers identified this as malicious, likely a phishing or trojan delivery mechanism. While no scripts were explicitly extracted, the PDF structure and numerous external links suggest it's designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://ketchas.ru/pbw?utm_term=olympiad+reasoning+book+pdf+free+download PDF link annotation
    • https://wenadexedodoren.weebly.com/uploads/1/3/4/3/134322255/velusuponatox-nipetapature-zubizep-rimiz.pdfIn PDF document text
    • https://towizitubozabo.weebly.com/uploads/1/3/5/4/135400713/labutipolu.pdfIn PDF document text
    • https://sivaxibekexisu.weebly.com/uploads/1/3/4/4/134488572/19dcdff26cf5a.pdfIn PDF document text
    • https://tipezigixak.weebly.com/uploads/1/3/4/3/134339593/73bb2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368770/normal_5fe4022669908.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487663/normal_5fd27b1b72ff5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464522/normal_60649b69545f0.pdfIn PDF document text
    • https://nonesuwenuvav.weebly.com/uploads/1/3/4/4/134400251/1641986.pdfIn PDF document text
    • https://zinikedefi.weebly.com/uploads/1/3/0/7/130740178/lefexexa-dozajut.pdfIn PDF document text
    • https://lulogozikojag.weebly.com/uploads/1/3/1/8/131858975/fofukudevozofifij.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425726/normal_6014903bae117.pdfIn PDF document text
    • https://piguvedulo.weebly.com/uploads/1/3/4/7/134724556/6bef76ddb8e.pdfIn PDF document text
    • https://visofebofoxofub.weebly.com/uploads/1/3/0/8/130814652/0928104c3cb8e5b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477156/normal_603fecc867ed6.pdfIn PDF document text
    • https://numuwawi.weebly.com/uploads/1/3/2/3/132303164/2937080.pdfIn PDF document text
    • https://nobarikanu.weebly.com/uploads/1/3/1/4/131483152/539578faa9cba.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://nijosifa.pbworks.com/w/file/fetch/145093443/jitij.pdfIn PDF document text
    • http://mujefapufefi.pbworks.com/w/file/fetch/144892164/62503119634.pdfIn PDF document text
    • http://murusefikuk.pbworks.com/w/file/fetch/145068402/valepuwalixowipuzerula.pdfIn PDF document text
    • http://nunaruribeg.pbworks.com/f/69091724120.pdfIn PDF document text
    • http://xovakovawup.pbworks.com/w/file/fetch/144521838/5_senses_used_in_descriptive_writing.pdfIn PDF document text
    • http://pagorevet.pbworks.com/w/file/fetch/144809910/mesotituwa.pdfIn PDF document text
    • http://tukufidanega.pbworks.com/w/file/fetch/144426324/bat_wings_pattern_printable.pdfIn PDF document text
    • http://kodalomibika.pbworks.com/w/file/fetch/145090761/20100381975.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e644.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE644 5784 bytes
SHA-256: da3a77294067aa3f12d367d47e3d03f8ee165a607b4fff3e3d74f8afa281db69
font_01_sfnt_off0000f9f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9F1 10716 bytes
SHA-256: 3ccb6312a741569bc5de8f022f6a5959339f523d2b72458aac3b23d282124d32
font_02_sfnt_off00011ea9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EA9 16164 bytes
SHA-256: 4bd16c8abd39118228c1571b0005d4eb3b3e943e572fd92a2a80cfcb7b749349