Malicious PDF — malware analysis report

Static analysis result for SHA-256 96b9520a5d1b6978…

MALICIOUS

PDF

90.9 KB Created: 2021-08-09 21:20:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e32b0e4c47df1667cc0669db483c32ca SHA-1: b35a625f3493e8b7840334ec4c8aa7fb6b9349d7 SHA-256: 96b9520a5d1b69786f364306fa999951832b3faf7ca3cf7957a3ecc3962ba78b
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting it's designed to lure users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for human readability but rather as a container for links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9876

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
  • 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://krisoc.ru/uplcv?utm_term=formula+para+sacar+volumen+de+un+prisma+triangular PDF link annotation
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16095a41d0ed05---tuxajusutol.pdfIn PDF document text
    • http://faxik.ru/ckfinder/userfiles/files/bojepogukutujama.pdfIn PDF document text
    • http://kperrylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/64753388270.pdfIn PDF document text
    • https://mayurherbal.com/userfiles/file/35034775771.pdfIn PDF document text
    • http://vejwun.cz/images/68716698512.pdfIn PDF document text
    • https://clinicscrm.com/img/files/63663534073.pdfIn PDF document text
    • http://mastera-mix.ru/ckfinder/userfiles/files/forexejara.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/jafupuliputekiburoxuxu.pdfIn PDF document text
    • http://dohertylaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/43891009910.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b78d5c2c30c---weleninojareparupuzigib.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddfc5ee54b---kepofurafibogijukowe.pdfIn PDF document text
    • http://hotelborgodeipoeti.com/userfiles/files/gutisabibisodu.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b6581badd35---rojig.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/5fce1d0546dfcdf2d8d165e0a9315fc6/71299676196.pdfIn PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/birosorogatarokaliso.pdfIn PDF document text
    • http://alburigiott.it/userfiles/files/50356086221.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdae094b215---37266019769.pdfIn PDF document text
    • http://kledingindex.nl/images/uploads/83635953566.pdfIn PDF document text
    • https://transport-vehicules.fr/userfiles/file/zafumobubenib.pdfIn PDF document text
    • https://castilloexterior.org/ckfinder/userfiles/files/22794199088.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fd0116ac669---foparamaxa.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084463b535b6---wawolewuzulipedavof.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/tapixugefejupibigune.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a98432a20d1---letokajatedu.pdfIn PDF document text
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/a372e30aa9ca54bb082496bf37d6c05a/duridevujumal.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/4956339497.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_off0000faed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAED 17972 bytes
SHA-256: ef60545ffa8ba95d75e0fa30db118f3ae93bfb4a5b7fbd2431d5c3658f798d0a
font_01_sfnt_off000128e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000140fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140FD 11000 bytes
SHA-256: e1f8cc134032ebb16fcdf145a724134c1995da06616908ae317ae357d6c47ed6