Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1b379d975df98c6…

MALICIOUS

PDF

89.4 KB Created: 2021-09-22 19:53:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 5397cea86164c864142a80f9d62ba25e SHA-1: e0aff91302c3f6f91fc188e7c447e698382e4bb1 SHA-256: c1b379d975df98c6baabff4665a8ab0a348da77a629e63e1a24bc706ee467989
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. The presence of numerous external URIs, many of which are embedded within the document's structure and appear to be part of a link farm, strongly suggests a phishing or malware distribution attempt. The file's metadata indicates it was generated by wkhtmltopdf, a tool often abused for creating malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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://nomylo.ru/uplcv?utm_term=every+skin+in+the+game+fortnite PDF link annotation
    • https://magerp.org/upload/files/fupebe.pdfIn PDF document text
    • http://iiiemjobs.com/FCK_Editor_Images/files/peduraba.pdfIn PDF document text
    • http://asu78.ru/userfiles/file/16795684528.pdfIn PDF document text
    • http://mamolenasnc.it/userfiles/files/savupefonugifare.pdfIn PDF document text
    • https://alansglobalservices.com/ckfinder/userfiles/files/napajinuwo.pdfIn PDF document text
    • http://klubalfa.org/img/userfiles/file/jorafumowemiwewijaga.pdfIn PDF document text
    • https://chetanaus.org/bheru/uploadfiles/file/sisokole.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/f7418604fe24ed6f9e7b27510c3cb28a/nosufijixu.pdfIn PDF document text
    • http://telektrans.hu/editor_up/68565129132.pdfIn PDF document text
    • http://hotel-ambassador-nice.com/upload/files/wowejawebulepebi.pdfIn PDF document text
    • http://22vek-omsk.ru/fck_editor_files/files/47222205526.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e800a7926b---gisivu.pdfIn PDF document text
    • https://exlite.it/ckfinder/userfiles/files/73791422827.pdfIn PDF document text
    • http://studio-orlandini.com/userfiles/files/3855725112.pdfIn PDF document text
    • http://xibuhuanyu.com/filespath/files/20210901152626.pdfIn PDF document text
    • http://gd-weimi.com/upfolder/e/files/20210917023353.pdfIn PDF document text
    • http://turksebruiloften.nl/userfiles/file/18973444627.pdfIn PDF document text
    • http://synphabase.ch/upload/file/90063895759.pdfIn PDF document text
    • http://wingtsunkungfu.ro/imagini_ws/92895376826.pdfIn PDF document text
    • https://akemi.ro/hirek/file/43099332022.pdfIn PDF document text
    • http://smolninskayahotel.com/userfiles/file/merezusamedi.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/73449881103.pdfIn PDF document text
    • http://zelene-centrum.cz/webpagebuilder/ckfinder/userfiles/files/15872031512.pdfIn PDF document text
    • https://musikkursus.dk/userfiles/file/rafudemo.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://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_off0000fcef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCEF 10872 bytes
SHA-256: f7491639ad3dc00a356e4610f79a5820112aad756dcd7691a8b38e8e4be66973
font_01_sfnt_off000115ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115EF 16264 bytes
SHA-256: 091e24de3863c5289c4b489cfb8da3cdcc3cf5087527d4d9a12bfccb40d4f9d5
font_02_sfnt_off00013fd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1