Malicious PDF — malware analysis report

Static analysis result for SHA-256 50335d6128dca145…

MALICIOUS

PDF

85.7 KB Created: 2021-09-16 06:14:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e7d57454692b28521575a44be0f41719 SHA-1: 4397cdf257f75604bb37cd58e0bd74ea01a6976b SHA-256: 50335d6128dca1459698b592e79a06dbdf47156e7e36a67a8a271b14f768e32d
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a large number of external URIs, many of which point to disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://allytemp.ru/uplcv?utm_term=funny+rv+gif PDF link annotation
    • http://perilatomsk.ru/ckfinder/userfiles/files/xutus.pdfIn PDF document text
    • http://perechen-jurnalov.ru/js/ckfinder/userfiles/files/dotigitapugamokem.pdfIn PDF document text
    • https://mahanakhon.pacedev.com/ckupload/files/notapuruto.pdfIn PDF document text
    • https://hutechsolar.com/upload/user_upload/files/45306775103.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134932e398e6---50625782864.pdfIn PDF document text
    • http://hotelrefah4ter.ir/basefile/hotelrefah4terir/files/96538578496.pdfIn PDF document text
    • http://nagakuratrading.com/js/upload/files/94657881238.pdfIn PDF document text
    • https://cottonweb.net/userfiles/file/kudasudisa.pdfIn PDF document text
    • http://longbienco.com/js/ckfinder/userfiles/files/35049561521.pdfIn PDF document text
    • http://gymostrov.org/gymostrov/userfiles/file/gifuxodesaxoxigukedo.pdfIn PDF document text
    • http://creaorganization.com/depo/sayfaresim/file/77474853901.pdfIn PDF document text
    • http://mg001.cn/upload_fck/file/2021-9-2/20210902093659618942.pdfIn PDF document text
    • https://betsin.org/userfiles/files/66399568926.pdfIn PDF document text
    • https://semangkabiji.com/contents/files/15569011853.pdfIn PDF document text
    • http://altus.pl/userfiles/file/semevagimube.pdfIn PDF document text
    • https://lifesmart.ro/ckfinder/userfiles/files/14321940541.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/60acf996076df67eed4af167c68bc30b/33438376977.pdfIn PDF document text
    • http://fk-fudosan.1nino3.com/app/webroot/img/userfiles/files/xujidudidesigu.pdfIn PDF document text
    • http://shevtsov-art.com/uploads/files/fexuxepivulo.pdfIn PDF document text
    • http://hieuchuan.com/upload/files/vubiwavazo.pdfIn PDF document text
    • https://parkettworld.com/upload/files/davozofuvidozipixi.pdfIn PDF document text
    • https://thietbidiensino.vn/media/ftp/file/vuretanosewemenul.pdfIn PDF document text
    • http://daegyung.kr/userfiles/file/20210903093050.pdfIn PDF document text
    • http://vakaruinzinerija.lt/userfiles/file/72229213115.pdfIn PDF document text
    • http://hoanggiaphatstone.com/upload/files/pinoviferapigiwewowe.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_off0000ebe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBE0 17820 bytes
SHA-256: fedef6c34cb59c0ceb67026f794e2282ad9799d5a9e2921e0bf066878c7a2b32
font_01_sfnt_off000119da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119DA 9920 bytes
SHA-256: 2996f1566839ad8028b5992f7c8e18e40181c03de8be54aa6473df01f67dd162
font_02_sfnt_off00012fc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FC7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1