Malicious PDF — malware analysis report

Static analysis result for SHA-256 743d31103d7920fb…

MALICIOUS

PDF

78.1 KB Created: 2021-10-05 14:47:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: aec5d611bd505c5dc110d2d19605848f SHA-1: 900d4798caba9d34eb72860a10e6e5d63e6c5b3f SHA-256: 743d31103d7920fb186e277c3c92cf95ed28e52f3c41c8a0a9438599cc129d4b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, forming a link farm. This suggests the document is designed to lure users to malicious sites, likely for phishing or to download further malware. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • 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.
  • 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://philabc.ru/uplcv?utm_term=examples+of+electronic+spreadsheet PDF link annotation
    • http://mathcountsoutreach.org/userfiles/file/52649189688.pdfIn PDF document text
    • http://intelekt.biz/uploads/pages/files/minakanizazaj.pdfIn PDF document text
    • http://euredit-editions.com/userfiles/file/faragezalul.pdfIn PDF document text
    • http://csc0851.com/userfiles/file/20210902044731_tuhbm5.pdfIn PDF document text
    • http://koreabulk.net/userData/board/file/wibivunir.pdfIn PDF document text
    • https://breedlife.com/upload/files/madepipi.pdfIn PDF document text
    • http://nissan.e-library.tw/uploads/files/3630059800.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/161509be5da46a---mazegoxib.pdfIn PDF document text
    • https://peintures-descours.fr/fichier/files/feparojonu.pdfIn PDF document text
    • http://buffagiuseppeinfissi.com/userfiles/files/3543737600.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/6567d6167fb04f134bdd299d81c0217e/28999613837.pdfIn PDF document text
    • https://fetogram.com/images/upload/files/wimam.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf57a2e151---marozafowoju.pdfIn PDF document text
    • http://wildzipper.com/clients/wildzipper/userfiles/file/8184367899.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/161350448ba333---xozupevo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613667b6dde0f---88204875353.pdfIn PDF document text
    • http://vasa-project.org/fckupload/file/fofomerumibezageririmu.pdfIn PDF document text
    • http://rgn2u.com/userfiles/files/13130758075.pdfIn PDF document text
    • http://perechen-jurnalov.ru/js/ckfinder/userfiles/files/dotigitapugamokem.pdfIn PDF document text
    • http://educaholistica.com/resources/img/imagesck/files/vurox.pdfIn PDF document text
    • http://zjleiou.com/images/upload/File/88849504007.pdfIn PDF document text
    • http://15449010.com/FileData/ckfinder/files/20210905_07791F8E7CD41C2A.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/52743907886.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_off0000cc6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC6B 17276 bytes
SHA-256: 267f21f86268e892227e424ce2741f494db55c2c86b610e1575e64388d006df0
font_01_sfnt_off0000f940.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF940 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011157.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11157 10968 bytes
SHA-256: a0160ab767ced580375a6f00d253cc4583ab4795d8964fc65807c895454914fe