Malicious PDF — malware analysis report

Static analysis result for SHA-256 c23f3108a200d88c…

MALICIOUS

PDF

79.8 KB Created: 2021-09-18 16:04:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1bc91308d7ecb1a707371d6c0969b4a7 SHA-1: ae991e5fc073161b212c11804f9c94d071f0e40b SHA-256: c23f3108a200d88ce9f5877ce3cac0f01af6d4391c1caadea25c08df51b161a1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF document flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. It contains numerous embedded URLs, with specific mention of a link farm on disposable hosting and a URL containing 'muscle booster apk premium hack apk', suggesting a lure for potentially unwanted or malicious software. The PDF structure and embedded URIs indicate an attempt to redirect users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 5

  • 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.
  • 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://catamma.ru/uplcv?utm_term=muscle+booster+apk+premium+hack+apk PDF link annotation
    • http://ehoron21.mn/uploads/files/61548068237.pdfIn PDF document text
    • https://medarbindia.org/ckfinder/userfiles/files/42224599263.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/12448490942.pdfIn PDF document text
    • http://laserbeautymachine.net/d/files/voxosuwigevudarelo.pdfIn PDF document text
    • https://krzczonowice.pl/gfx/file/mevanogawozamijatiw.pdfIn PDF document text
    • https://braindevelopmentmaps.org/userfiles/files/lixupakabelodepeme.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/ks2m2okvrtaq84457j4m0dg2a1/89071781084.pdfIn PDF document text
    • http://matsonconstruction.net/userfiles/file/vugabapab.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/7030959320.pdfIn PDF document text
    • https://sharjahcements.com/images/bulk_images/files/44641685712.pdfIn PDF document text
    • http://arsvet.ru/img/upload/pawunuv.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/worakofitazojiguvo.pdfIn PDF document text
    • http://youngthisyear.com/ckfinder/userfiles/files/3134512815.pdfIn PDF document text
    • http://hanasushichoice.com/uploads/files/tewele.pdfIn PDF document text
    • http://bagiez.com/userfiles/file/nitujuduka.pdfIn PDF document text
    • http://xn--80aa5alfu.kz/file/21800419884.pdfIn PDF document text
    • http://ukrfirework.com/images/file/saxaxinaxobumisupim.pdfIn PDF document text
    • http://aexpress.lv/index/images/up/file/komuzimalesu.pdfIn PDF document text
    • http://myepres.com/HotelEstimator/userfiles/file/84948217075.pdfIn PDF document text
    • http://rotarytattoomachine.co/project-new/christianbook/upload_images/file/92347896713.pdfIn PDF document text
    • http://fortwashington.abwingsmd.com/uploads/files/26806077392.pdfIn PDF document text
    • http://stowarzyszeniemalyksiaze.eu/img/upload/files/14610692477.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/bowukapozemapid.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143b507e0f9e---45220344577.pdfIn PDF document text
    • http://hotelbelleepoque.bg/userfiles/file/53242216858.pdfIn PDF document text
    • https://markyatirim.com/resimler/files/fewojovudid.pdfIn PDF document text
    • http://wellogo.in/userfiles/file///11398919938.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_off0000cea6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEA6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6B8 19108 bytes
SHA-256: d73a4fcb71c18224f1832345cbc2af80c74303c632a234e613fe718a26f68de9
font_02_sfnt_off000118bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118BB 10860 bytes
SHA-256: d9f3e16467f42e37aa51d4342c6eb52e79cb0b0407ad16a99ea2154bd901dd8f