Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a745a6af0a6b13…

MALICIOUS

PDF

71.4 KB Created: 2021-09-19 14:50:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c6833e1b809ccc63970bb00f10a1d1b1 SHA-1: 1a85c48864a6aef4a59b20952fccf5a19f5c5257 SHA-256: 81a745a6af0a6b1368c20e224ed7421370f477b64189aeace58be6d2ba68c323
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is designed to host numerous links on disposable domains, a common tactic for phishing or distributing further malware. While no scripts were explicitly extracted, the presence of many external URIs suggests the document's primary function is to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://crysiq.ru/uplcv?utm_term=restart+my+phone+now PDF link annotation
    • http://ppogrimall.com/upload/editor_image/file/jogamosusele.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/74144562737.pdfIn PDF document text
    • https://www.ewdel.cz/ckfinder/userfiles/files/fikanisawo.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-1/20210901175159679953.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/161397f244c23c---94949859421.pdfIn PDF document text
    • https://sistemkabin.com/ckfinder/userfiles/files/fifeloxajukipafejomog.pdfIn PDF document text
    • https://www.aaptuk.org/ckfinder/userfiles/files/70924554311.pdfIn PDF document text
    • http://xn--4k0b43gkwo4gn.com/upload/editor/file/87338514588.pdfIn PDF document text
    • https://kccegis.com/upfiles/content/file/20210905050151.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/pojufufuw.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/42028770085.pdfIn PDF document text
    • http://bloemenwinkelindex.nl/images/uploads/fitofoja.pdfIn PDF document text
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/fexenunemojewawo.pdfIn PDF document text
    • http://cngwalk.com/fckeditor/userfiles/image/zegamobukezogesumemopesab.pdfIn PDF document text
    • http://hzqljsj.com/images/upload/File/sovefexakuginu.pdfIn PDF document text
    • http://sushrutproctology.org/ckfinder/userfiles/files/tewoduluf.pdfIn PDF document text
    • https://godparents4tz.org/home/god/public_html/ckfinder/userfiles/files/24902786329.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161351415745a6---73374314193.pdfIn PDF document text
    • http://onnetsolution.in/userfiles/file/jirunaxiz.pdfIn PDF document text
    • https://plewmal-d.com/Uploads/files/lofifupapalijutapite.pdfIn PDF document text
    • https://ateliersmq.com/pevron/www/img/file/vogasixenudujivi.pdfIn PDF document text
    • http://stavo-bazar.cz/userfiles/file/87887544870.pdfIn PDF document text
    • http://swvocal.com/data/se2/file/bilokujelilipiniwi.pdfIn PDF document text
    • https://rewaqousha.net/userfiles/files/84501134157.pdfIn PDF document text
    • http://yigang-lin.com/uploads/files/202109160251514796.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_off0000b8ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d0c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0C0 15452 bytes
SHA-256: e1dce9f69e3d3b068f20d4f02938a29b5f7d91c74e03e571747f40c22e6907b9
font_02_sfnt_off0000f7c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7C2 10624 bytes
SHA-256: ff4c55ec0b76f014d9adb8daeccda59b8c299d4961d2ff18cc4f7a17f08c6a57