Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb256c19d305b267…

MALICIOUS

PDF

70.8 KB Created: 2021-09-27 12:44:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1c3de05b40ed7dcd869a46899dd9a2df SHA-1: 2ada36cdc42c449752a7202ba867576d12658fc6 SHA-256: fb256c19d305b267eefb0e14a441771c14907e2878bd46e25cb01449d8b8048a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and multiple external URIs, including one that appears to be a download link for 'vlc app apk download'. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates the document is part of a link farm on disposable hosting, further suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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 https://synerhu.ru/uplcv?utm_term=vlc+app+apk+download PDF link annotation
    • http://prplus4u.com/ckupload/files/wagid.pdfIn PDF document text
    • http://avvolodin.ru/upload/file/nirizugunutulupeba.pdfIn PDF document text
    • https://kimcert.org/E/file/kezalepopozulubut.pdfIn PDF document text
    • http://olsztyntransportmedyczny.pl/userfiles/file/jogetigibosaviwese.pdfIn PDF document text
    • https://www.auto-ecole-acm.com/ckfinder/userfiles/files/dukidaxerokovevezabaki.pdfIn PDF document text
    • http://musclecar-taps.com/js/upload/files/gijejogenumukifig.pdfIn PDF document text
    • https://perfecthospitals.com/FCKeditor/file/sanozekef.pdfIn PDF document text
    • https://specializedfacilitymgt.com/public_html/userfiles/file/34320185047.pdfIn PDF document text
    • http://quaisetoiles.fr/img_pages/file/40780877609.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__613254D37D250.pdfIn PDF document text
    • http://wohntraumgmbh.at/88108696303.pdfIn PDF document text
    • http://terezszilvia.com/images/uploaded/file/xezakarinifi.pdfIn PDF document text
    • https://markapin.com/calisma2/files/uploads/jufedi.pdfIn PDF document text
    • http://abwingsjanaf.com/uploads/files/moxabarabufebuxotubox.pdfIn PDF document text
    • http://yuilchem.com/userData/board/file/koselinewisavivuges.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/116695c9c3df8b905ee9cc8ebf85a137/sunajatiruvaj.pdfIn PDF document text
    • http://fleshlight-tw.com/userfiles/file/51766713370.pdfIn PDF document text
    • http://onishi-kyosendo.jp/archive/babug.pdfIn PDF document text
    • http://vasvaripalmuzeum.hu/upload/file/namir.pdfIn PDF document text
    • https://lesura.net/userfiles/file/bupefunufi.pdfIn PDF document text
    • http://sasmedm.com/www/js/ckfinder/userfiles/files/43702992425.pdfIn PDF document text
    • https://erdemlerkoleji.com/resimler/files/50769612958.pdfIn PDF document text
    • http://quocteanviet.com/img-chamthi/files/babesojonuzitabavimuz.pdfIn PDF document text
    • http://olympicburger1988.com/uploads/files/76981784067.pdfIn PDF document text
    • https://loyallcanada.net/editor_files/file/nalizutomekizifosog.pdfIn PDF document text
    • http://www.bufolari.com/public/immagini/file/53505508526.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_off0000b279.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB279 10064 bytes
SHA-256: 99b99560bd5f907a88cdcfbbebca4040dd8e4603532a4ea6ac6dc227b3b153bb
font_01_sfnt_off0000c908.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC908 17860 bytes
SHA-256: ca02c4d68466e1f331c7945405cfd7e79e35931647803385f5e53d65f37e00e2
font_02_sfnt_off0000f5d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1