Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfcb32ca21d9608d…

MALICIOUS

PDF

85.9 KB Created: 2021-09-09 00:02:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 96f3939b5de219f13421247a5f25db6d SHA-1: 12dde942c9f72b5ec99a3df8cd24c8eb3d19dd9c SHA-256: dfcb32ca21d9608df7660b7b8f87a113e08bbba3c8ddb3a96acf6825d94fded1
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which point to disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO abuse. The embedded JavaScript may be used to further obfuscate the malicious redirection or download additional payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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
  • 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 http://doudou.tw/userfiles/files/42600793558.pdf In PDF document text
    • http://18554080.com/userfiles/file/3010454136.pdfIn PDF document text
    • http://vendsol.com/userfiles/file/15464827982.pdfIn PDF document text
    • http://chernogolovka.inhome360.ru/admin/ckfinder/userfiles/files/74611753267.pdfIn PDF document text
    • http://gillsandgeckos.com/userfiles/file/dagizelijezitakoxe.pdfIn PDF document text
    • http://barsugo.com/ckfinder/userfiles/files/52147902041.pdfIn PDF document text
    • http://hilimall.ae/uploads/files/10368788165.pdfIn PDF document text
    • http://ominocoibaffi.it/userfiles/files/kuvadijojuge.pdfIn PDF document text
    • http://freeorden.com/media/file/79306175090.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/61664633674.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/korufebodigesofok.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/00a629f274df2ddf32dd6a101295c033/soviwizika.pdfIn PDF document text
    • http://yingtailong.com/upload/file/210908233442067900zh9r0fy8bewp.pdfIn PDF document text
    • https://newsale.linyn.mobi/upload/ckeditor/pages/files/xesamegemax.pdfIn PDF document text
    • http://alituncer.com/userfiles/file/befibudivadulolaligevas.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/83024363892.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/gemawaravoralumeki.pdfIn PDF document text
    • http://golfproradost.cz/webpagebuilder/ckfinder/userfiles/files/duzawuvisoputokanimetapiw.pdfIn PDF document text
    • https://grouptm2.com/contents/files/54931245049.pdfIn PDF document text
    • http://cungcapluonech.com/upload/files/gudelefodowuluzal.pdfIn PDF document text
    • http://satcomlink.com/userData/board/file/xemelebuko.pdfIn PDF document text
    • https://costarica4d.com/contents/files/65650181189.pdfIn PDF document text
    • https://reaga.net/js/ckfinder/userfiles/files/bilijupuzor.pdfIn PDF document text
    • http://kfnmsz.com/upfolder/e/files/20210909003009.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613060ff2a671---78938074498.pdfIn PDF document text
    • http://elandtour.com/FileData/ckfinder/files/20210902_ABD9AB3E756CCE1E.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=best+facebook+hacker+apps+for+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_off0000eaa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAA0 10956 bytes
SHA-256: 661c33c236d2f982aa2a0a2f07a344721fd724f257a60b482bd489d83e8db3e8
font_01_sfnt_off000103d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011be8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BE8 17772 bytes
SHA-256: 81eef91dab92007c90e816d37528632e23dd3d3cfc9944f79c00c15017c9dd36