Malicious PDF — malware analysis report

Static analysis result for SHA-256 31ec662a17ee2303…

MALICIOUS

PDF

82.0 KB Created: 2021-03-22 21:07:07 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 8200485cb65434e010c437ca7303b770 SHA-1: d1ef560739827ba133100930a1c5d5b694e827c5 SHA-256: 31ec662a17ee2303c3eb6eb0b78878b855d1224ff53741b584e560f877528336
184 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by multiple heuristics, including a critical finding for linking to known malicious redirector infrastructure. The embedded links, such as 'https://yafferge.ru/strik?utm_term=is+killing+floor+2+cross+platform+xbox+and+pc', are designed to redirect users to potentially harmful sites. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often abused for creating malicious PDFs.

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/strik?utm_term=is+killing+floor+2+cross+platform+xbox+and+pc In PDF document text
    • http://venatukuberelo.iblogger.org/fuderezotisetu.pdfIn PDF document text
    • http://vorusobowa.66ghz.com/98126272099.pdfIn PDF document text
    • http://nuvekediporere.22web.org/50085368689.pdfIn PDF document text
    • http://tamakar.tech/sabre_dance_piano_sheet_music2l6hr.pdfIn PDF document text
    • http://mini-cam1.club/straddling_the_line_jaci_burton_espaol1utdk.pdfIn PDF document text
    • http://sibasijiv.22web.org/69189383009.pdfIn PDF document text
    • http://uscovidcharts.com/rozutejizi1ogto.pdfIn PDF document text
    • http://duxeluwezix.iblogger.org/mulawanenovi.pdfIn PDF document text
    • http://nojolavu.22web.org/50444295053.pdfIn PDF document text
    • http://bedusopuzal.22web.org/armoury_crate_asus.pdfIn PDF document text
    • http://bufenukaje.22web.org/how_to_adjust_kitchenaid_artisan_mixer.pdfIn PDF document text
    • http://oneshops.space/94263805626xwz9f.pdfIn PDF document text
    • http://sibuvre.com/56735227127sfmcz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://pukupufiribeja.epizy.com/40979920785.pdfIn PDF document text
    • http://susupufewowe.epizy.com/simone_beauvoir_livros.pdfIn PDF document text
    • http://limepupotof.epizy.com/30554305703.pdfIn PDF document text
    • http://niwanabumupe.epizy.com/americas_mailbox_forms.pdfIn PDF document text
    • http://wopugizejaru.rf.gd/70190075980.pdfIn PDF document text
    • http://melaworogafema.epizy.com/mukano.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_off0000eb5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB5A 5816 bytes
SHA-256: bc396cf2c80cd4797d8778c337eb671213bf7e77efd8c2cc923b94989eb990c1
font_01_sfnt_off0000ff16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF16 11656 bytes
SHA-256: 9d6a6ff89a6b495bb238279aac670d5de42020f295bc7ee3b25de9c59c0acdce
font_02_sfnt_off00012557.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12557 16204 bytes
SHA-256: 541fa2b6826b0add99b7d5a173ef1e6a5567607b5192f75b810eb17d6a563501