Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cdb346ff518fa78…

MALICIOUS

PDF

71.1 KB Created: 2021-09-10 07:46:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 691f80c728e2925bad516729daa4e031 SHA-1: d12803bb9ad1b0c302cd36402df1af5a2ec2d29d SHA-256: 4cdb346ff518fa7886cb55ceedeabee1d46c06dbf70d38b4571078fd685fcaec
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The document also features a large number of external URLs, many of which appear to be part of a link farm, suggesting an attempt to direct users to potentially harmful websites. The presence of embedded JavaScript indicates an intent to perform actions beyond simply displaying content, likely related to downloading further payloads or redirecting users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://huntic.ru/uplcv?utm_term=best+cache+cleaner+for+android PDF link annotation
    • http://www.thaitofu.com/image/upload/File/xomef.pdfIn PDF document text
    • https://tedvandergulik.nl/userimages/file/vigilokoxejum.pdfIn PDF document text
    • http://iphonedown.com/ckfinder/userfiles/files/raruvaves.pdfIn PDF document text
    • https://handinhand-daycare.com/ckfinder/userfiles/files/25877251834.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/63136004957.pdfIn PDF document text
    • http://cafemsoffice.com/userfiles/files/pupalukewusogozepidule.pdfIn PDF document text
    • http://drtamerturan.com/file/94432954425.pdfIn PDF document text
    • http://koreaseals.com/ckfinder/userfiles/files/77862235854.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f5f433da4---rejavunifuposuwumexogi.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/siwibabolaxunevidufi.pdfIn PDF document text
    • https://marblobathware.ph/app/webroot/img/files/zimiwuged.pdfIn PDF document text
    • https://yaofangpeixun.com/upload/files/94574897064.pdfIn PDF document text
    • https://autoradiator.mn/uploads/ckfinder/files/lakebejipan.pdfIn PDF document text
    • https://gemma.lucien-sv.info/uploads/files/61370d32569b3.pdfIn PDF document text
    • https://daulte.com/ckfinder/userfiles/files/3872163575.pdfIn PDF document text
    • http://sun-marche.com/app/webroot/js/ckfinder/userfiles/files/91326828226.pdfIn PDF document text
    • https://worldmedglobal.com/userfiles/files/mepowebibogexuzuzimad.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/51478139741.pdfIn PDF document text
    • http://flixgolf.com/ckeditor/ckfinder/userfiles/files/nokemuwil.pdfIn PDF document text
    • http://isvpro.com/custom/files/11311878818.pdfIn PDF document text
    • https://www.sensormaticltd.com/app/templates/js/ckfinder/userfiles/files/fozojigalen.pdfIn PDF document text
    • http://studioboscono.it/userfiles/files/vogukilexemanoderitavaz.pdfIn PDF document text
    • http://jungvassar.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/josaxemininaj.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/69l6cbjhplaj1t1u0b15mnaih5/77850177533.pdfIn PDF document text
    • http://rpsbchamber.org/editorData/file/34562091741.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_off0000b612.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB612 15640 bytes
SHA-256: 403715dc92a43d941c086e7f7030c2658213468f991986c4786ba3768c985426
font_01_sfnt_off0000de04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE04 10628 bytes
SHA-256: 86b8b61e1191f79547b307f3c7d1176cfea0ae43db22d3cb5134a97013c1929e
font_02_sfnt_off0000f648.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF648 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1