Malicious PDF — malware analysis report

Static analysis result for SHA-256 adc778e910033473…

MALICIOUS

PDF

75.1 KB Created: 2021-09-13 16:15:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 7842490768b041e188d011907ed9c24c SHA-1: 204c26c8a9e12413ff8ea321574472b6e81ba623 SHA-256: adc778e910033473d561f60172acf3e324682d2912a78c999193b2a6c6001835
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised websites or disposable hosting. Some links lead to PDFs hosted on compromised WordPress upload directories, suggesting a multi-stage attack.

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 http://dekobonner.de/userfiles/file/kudatiwekukuwe.pdf In PDF document text
    • http://xinghui.co/upload/ckimg/files/202109011359274021.pdfIn PDF document text
    • http://ues-rb.ru/themes/ues-rb.ru/files/95733105748.pdfIn PDF document text
    • http://aroma-es.red/yamituki-n/uploads/files/xitomezu.pdfIn PDF document text
    • http://mikllc.mn/uploads/files/gafitanepetoda.pdfIn PDF document text
    • https://doitoutdoorz.com/file/mMLAzEj5PEK6QE2z.pdfIn PDF document text
    • http://dallard.fr/ressource/site-image/files/genatat.pdfIn PDF document text
    • https://avukat.dnsaktif.net/upload/files/rokalanamijusu.pdfIn PDF document text
    • http://elcolono.net/userfiles/files/gabibufifomanofokuda.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/895df1a750e7c05c6d07ebd06c64aaea/57597430784.pdfIn PDF document text
    • https://goldengatetaichiqigong.com/userfiles/file/7595064932.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135c32c7ce23---83161039118.pdfIn PDF document text
    • http://suvagcentr.ru/userfiles/files/78158737239.pdfIn PDF document text
    • http://qtjdb.com/UploadFile/2021/09/07/file/20210907_044846_187.pdfIn PDF document text
    • http://ymmicro.com/files/files/nopulavudixagofe.pdfIn PDF document text
    • https://preciseenergygroup.com/media/80858327115.pdfIn PDF document text
    • http://sspvjd.com/FileData/ckfinder/files/20210905_6E27419541B34FA7.pdfIn PDF document text
    • https://upaspor.com/resimler/files/wotidero.pdfIn PDF document text
    • http://hockeydh.com/files/ups/files/3696577481.pdfIn PDF document text
    • http://hla.vn/upload/files/zekomov.pdfIn PDF document text
    • https://hattoco.vn/images/ckeditor/files/nemiji.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/fcdffccbae95216290db121363d45bcf/toxukolezajumesigiwa.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/33b3e9c58feae82bc6fe61c83e3248f6/lasitikuwefusokafogo.pdfIn PDF document text
    • http://shiokuda1.com/contents/files/3820143467.pdfIn PDF document text
    • http://palami.by/images/file/rawuwipinazatipeses.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=como+excluir+gmail+do+androidPDF 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_off0000c280.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC280 10680 bytes
SHA-256: 7b16e3e84a53fd7c1668808b305064f6ed2f07bb9251ae3655743035be312807
font_01_sfnt_off0000dab9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAB9 16908 bytes
SHA-256: c8eb085504586189efbd46f1778463033f1ab677ef863d299ed101790e6c6066
font_02_sfnt_off00010659.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10659 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1