Malicious PDF — malware analysis report

Static analysis result for SHA-256 a99d84bc8124305c…

MALICIOUS

PDF

80.9 KB Created: 2021-09-18 06:29:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 17f530f8aad50089d945440d8af4a593 SHA-1: 60d9750cb3ae27c6e77a133c6f33514c81b986a7 SHA-256: a99d84bc8124305c99db0761e962b84a555e4bd9d06caf02c33986e6279e200d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external URLs, many pointing to compromised websites or disposable hosting, indicating a link farm designed to redirect users. ClamAV and ML classifiers strongly indicate malicious intent, likely phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 7

  • 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 link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://pistant.ru/uplcv?utm_term=themes+manager+for+samsung+emoji+iphone PDF link annotation
    • http://ff-engineering.com/userfiles/files/61346792743.pdfIn PDF document text
    • http://dunajecbiala.pl/upload/File/46824565153.pdfIn PDF document text
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/vuragadijex.pdfIn PDF document text
    • http://xn--80akoseq9f.xn--p1ai/userfiles/file/97956812425.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/b0c7caa9fa2674e1a386dc7779a077a0/vivev.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613918997ab25---rewirodotebunulifo.pdfIn PDF document text
    • https://agermag.ro/mm/file/sitepodudasoko.pdfIn PDF document text
    • http://cedule-plachty.cz/files/file/392080864.pdfIn PDF document text
    • http://www.vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/zelolegexaliximofa.pdfIn PDF document text
    • https://www.habitat-morvan.fr/ckfinder/userfiles/files/xetixibaxukatopivi.pdfIn PDF document text
    • http://hoangminhsaigon.vn/@dmin/js/ckfinder/userfiles/files/97431568700.pdfIn PDF document text
    • https://a-1commercialkitchenservices.com/ckfinder/userfiles/files/70924235832.pdfIn PDF document text
    • http://www.donboscovizag.org/images/files/66403398920.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16145057b9350a---69952428599.pdfIn PDF document text
    • http://cityfate.com/files/files/17661475960.pdfIn PDF document text
    • http://coyada.com/up_images/up_images/pebubikajukud.pdfIn PDF document text
    • http://fitviewer.com/files/file/44224572573.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/wakifumiwox.pdfIn PDF document text
    • http://ecolservizinettuno.com/userfiles/files/mineloj.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-17/20210917093329456130.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_off0000d552.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD552 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED64 18412 bytes
SHA-256: 2ec2fe1b631cbf2f9b229dcaa92ee5bfda769d673a62f527ea505dc408df706b
font_02_sfnt_off00011d32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D32 10852 bytes
SHA-256: b33b3291fb988b3dd569ab130986ab12b2483088a5975e57190e3700cf013d04