Malicious PDF — malware analysis report

Static analysis result for SHA-256 a75bfb0dc57f1a44…

MALICIOUS

PDF

79.9 KB Created: 2021-09-14 07:48:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6dd9fe8a2423fe1fffcbb90e0b264d46 SHA-1: f3cd508fad3508b639612ed5ae07ab902a915fb1 SHA-256: a75bfb0dc57f1a446d5cce2184b7cd5930e21c5d2fac8ad0eb183b4ed584fbe0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

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 URLs pointing to compromised CMS upload directories, suggesting an attempt to lure users to malicious content. The presence of multiple external URIs and the nature of the heuristics strongly suggest this PDF is part of a phishing campaign, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16137e027ef968---tewusutenenovexotozejivav.pdf In PDF document text
    • http://www.beautyvogue.ch/Files/file/77624900081.pdfIn PDF document text
    • http://dotbamboo.com/file_media/file_image/file/difatibabiwarad.pdfIn PDF document text
    • https://inverpalmas.com/aym_image/files/jubisibubotunabexodoxav.pdfIn PDF document text
    • https://cfi-registration.amyhalter.com/buzzboxgift/img/userfiles/files/wumesoselogor.pdfIn PDF document text
    • https://annekienlen.fr/imagesfile/mubux.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130146c44f0f---75453259263.pdfIn PDF document text
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/doxosariselibobipesite.pdfIn PDF document text
    • https://viceda.com/userfiles/file/wufikulekikote.pdfIn PDF document text
    • https://autoteam.in/ckfinder/userfiles/files/loluwizamojogeke.pdfIn PDF document text
    • http://elektrostroy.kz/ckfinder/userfiles/files/wimejevatemotuvi.pdfIn PDF document text
    • http://mrs724.ir/basefile/drtiketcom/files/ninebojosasime.pdfIn PDF document text
    • http://bischofs-scheune.de/userfiles/file/vajizob.pdfIn PDF document text
    • http://yoron.net/up/files/57265039701.pdfIn PDF document text
    • http://the100voicesofgospel.ch/fichiers/newsletter/file/74932562580.pdfIn PDF document text
    • http://aviteksural.ru/admin/ckfinder/userfiles/files/14788166610.pdfIn PDF document text
    • http://sunpix.ru/img/lib/file/nebigipavojof.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/gogewawaviluwedopi.pdfIn PDF document text
    • https://www.highlandernepal.com/assets/ckfinder/userfiles/files/99266480449.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161369f97a1a44---jukawonodesodazenozuzafi.pdfIn PDF document text
    • http://amunt.madteam.net/ckfinder/userfiles/files/liwumokiledirakone.pdfIn PDF document text
    • http://vigova.com/Images_upload/files/zugexulufomebodane.pdfIn PDF document text
    • http://tieulongcopro.com/luutru/files/jilusuposi.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb0d539149---60420170649.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=android+add+site+to+home+screenPDF 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_off0000d307.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD307 18528 bytes
SHA-256: 7acbc86067b26038ee61a18a57eeda2c3556827ffdae514ba26d7016bb08ec94
font_01_sfnt_off0001027c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1027C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A93 10568 bytes
SHA-256: 3f734914c7697cceb01ebf96afad9e8bee78a61637f81caf42820e64108886eb