Malicious PDF — malware analysis report

Static analysis result for SHA-256 a380d141b7fed93e…

MALICIOUS

PDF

85.8 KB Created: 2021-09-11 05:42:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 473a46dcd62ef456def75e0da334462b SHA-1: 5367e9b87133dfb87de02bc39e1b10884b83be56 SHA-256: a380d141b7fed93ef12f1f2c0836acd11b24af97056868834c428c7ef77c9dca
126 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm. The embedded URLs, despite some being marked benign, point to a pattern of distributing content through numerous domains. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose, which is likely phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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 http://alanaf.ru/userfiles/files/32726281757.pdf In PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/29baca42dc66d3419a2e83c96b9d8789/zavajusemijaveri.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///66539885965.pdfIn PDF document text
    • https://sadex.pl/fck/file/94806498745.pdfIn PDF document text
    • http://tzsunup.com/upload/momokulawukokokotub.pdfIn PDF document text
    • http://kuresi-kaitori.com/upload/content_pic/files/givofu.pdfIn PDF document text
    • https://livstyle.ro/home/livstyle/public_html/uploads/files/zopetopujufoduwupotol.pdfIn PDF document text
    • http://stavclearing.ru/upload/files/49297776052.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16136f6852a771---88525837499.pdfIn PDF document text
    • http://dkmmotor.com/files/userfiles/file/pobepofogurugepako.pdfIn PDF document text
    • https://chambredhotes-savoie.com/ckfinder/userfiles/files/42213872697.pdfIn PDF document text
    • https://thehouseconcert.com/ckfinder/userfiles/files/44292876262.pdfIn PDF document text
    • https://yourdentist.ro/app/webroot/files/userfiles/files/gutopisojawilar.pdfIn PDF document text
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/nuduwixavevujegulazikebab.pdfIn PDF document text
    • http://caythuocnam.org/images/files/15748403363.pdfIn PDF document text
    • https://leavereview.com/customerinterview/ckfinder/userfiles/files/59353210075.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/sibiwo.pdfIn PDF document text
    • https://vinadesigndanang.vn/uploads/image/files/96709739201.pdfIn PDF document text
    • https://gmt-tw.com/app/webroot/userfiles/files/9269707372.pdfIn PDF document text
    • http://marcus-1.com/FileData/ckfinder/files/20210911_310875AA49AB3D81.pdfIn PDF document text
    • https://dintek.eu/uploads/file/sudinukodufemawuvif.pdfIn PDF document text
    • http://gulfcoastlist.com/userfiles/file/42937437132.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=rocitizens+clothes+codesPDF link annotation
    • 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_off0000e957.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE957 18976 bytes
SHA-256: aa080452271ccaf8950658dc3c49ad6130a8a4660aa4b7ddf9fbc2b0285a4352
font_01_sfnt_off00011aaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AAF 10312 bytes
SHA-256: 18474ebf83727734645d086eb3eee28993fb51564c9ed5a44c007ff925b7c3c7
font_02_sfnt_off000131e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1