Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8d23f6d5a25d570…

MALICIOUS

PDF

87.4 KB Created: 2021-09-01 16:35:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 672657215abbab3697e58b889e566466 SHA-1: 22a3f7ad5d82408269d800134064466d7be6632d SHA-256: f8d23f6d5a25d570c6be73290d44f11eb7f09d0061b2b5c3609057279766f19d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ClamAV and an ML classifier. It contains numerous links, many pointing to compromised WordPress sites, suggesting it functions as a link farm. The presence of multiple distinct hosts and the use of 'utm_term' parameters indicate an attempt to distribute traffic or phish users. No scripts were extracted, and the document body was unreadable, but the link farm heuristic strongly suggests a malicious intent to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://yourlightingbrand.com/wp-content/plugins/super-forms/uploads/php/files/5e37e0f28c6e6d182cf00698146e0146/95655365452.pdf In PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608351b738cd7---79323822612.pdfIn PDF document text
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/4a18bf62c453f0459b2ce66f8d827eb4/81749024323.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070b3da4eabc---desosul.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd7c498b99---busikivotugajusoborux.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/79096056965.pdfIn PDF document text
    • http://china-zub.ru/userfiles/file/xifaxufenokofezilonejag.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/f8dac42ee79404c4361c9125a7b78661/71176678070.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609452e564234---kewamopogaxoxukezunesupex.pdfIn PDF document text
    • http://www.aadhar-interior.com/userfiles/file/53435766121.pdfIn PDF document text
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/vegoxekupomanepuwomon.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/79984382209.pdfIn PDF document text
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210717220353.pdfIn PDF document text
    • http://blueyee.com/upload/file/250214533043.pdfIn PDF document text
    • https://prtl.pl/userfiles/file/vugegisuloxusijib.pdfIn PDF document text
    • http://dwallacelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/susixinum.pdfIn PDF document text
    • http://xn----7sbakn3aoflleitf3m6a.xn--p1ai/userfiles/file/wokaxibapigogenata.pdfIn PDF document text
    • http://laser-piskovani.cz/democms/userfiles/file/kazibusaresijikuvefuxifu.pdfIn PDF document text
    • https://livres-d-art.com/ckfinder/userfiles/files/34873459129.pdfIn PDF document text
    • http://vonschickenconcord.com/uploads/files/29635118651.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/35cfabfd9f09876fb1181751afec1149/8749794143.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/3f440b8ea544b8f144663ba59f8a6d7a/42250870600.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/lef6smm36kkq7loiikmqh87v65/43021892946.pdfIn PDF document text
    • http://studiotecniconuti.it/userfiles/files/keregixitifubijugo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=it+puts+the+lotion+on+the+skin+quotePDF 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_off0000f16f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF16F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010986.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10986 10376 bytes
SHA-256: 6d3dfebaf3861bbfc18ff1232be816f9663bca9f1cc08fd8483718922069a2e0
font_02_sfnt_off000120e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120E3 18184 bytes
SHA-256: b54178dbdcabf3d08b23923b0ad4cec043d444d6c8acada807acf09b90e69203