Malicious PDF — malware analysis report

Static analysis result for SHA-256 426a03dba7cb5b92…

MALICIOUS

PDF

89.0 KB Created: 2021-02-11 08:50:03 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 3f23154c0220ec8dd022e64c7eae2bc5 SHA-1: a2528e42887244991814f35aac70b86e24ef3341 SHA-256: 426a03dba7cb5b92391cf15e315a915944beb540d73ed849477f639859d56eb0
184 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link pointing to 'https://yafferge.ru/infin?keyword=c+wpf+expander+template'. The ML classifier also strongly indicated maliciousness. While no scripts were extracted, the presence of a malicious URL strongly suggests an attempt to lure the user to a harmful site, likely as part of a phishing or malware delivery scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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 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://yafferge.ru/infin?keyword=c+wpf+expander+template In PDF document text
    • https://static.s123-cdn-static.com/uploads/4369764/normal_5fcc37903d43b.pdfIn PDF document text
    • http://fijeveg.iblogger.org/wodexepese.pdfIn PDF document text
    • http://kataeta.club/3389643236dd219.pdfIn PDF document text
    • http://simcars.ru/wagon_wheel_violin_sheet_music_darius_ruckerc1d4z.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4464083/normal_6002ed10ea003.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413363/normal_600616425a979.pdfIn PDF document text
    • http://sokinabunerir.iblogger.org/java_jdk_linux_mint.pdfIn PDF document text
    • http://strahuemsya.info/327108325115ca0g.pdfIn PDF document text
    • http://moviesaddaa.online/wewexusoveoix2f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379222/normal_5fc7c5d7485ba.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/kasuwevovog/kajalelosul.pdfIn PDF document text
    • http://vuruketunuwu.epizy.com/bhopal_express_hd_movie.pdfIn PDF document text
    • https://s3.amazonaws.com/xasovewipeje/sing_gary_barlow_piano_sheet_music.pdfIn PDF document text
    • https://s3.amazonaws.com/wupuxus/guvusedopikibibesif.pdfIn PDF document text
    • http://wozawexopad.epizy.com/bhulekh_mp_app.pdfIn PDF document text
    • https://s3.amazonaws.com/dikobepibelun/50943604735.pdfIn PDF document text
    • https://s3.amazonaws.com/tosego/75878811.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_off00011332.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11332 5076 bytes
SHA-256: 7e9f257e1ac11265ea3ca6baf617f6e619f2b7efe4d9bee980a49138db88fe72
font_01_sfnt_off00012474.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12474 15396 bytes
SHA-256: 9cb115562d427602e2a57a7197cba3f30e7cf3cf03999a4835e1cb03531dbfc2