Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8b9bec1b663f063…

MALICIOUS

PDF

76.4 KB Created: 2021-09-13 13:48:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4fa5b6e8bd786699e3255289c8d6b5fb SHA-1: c01e3a71af17c46430025c7796bd7c63816e424a SHA-256: f8b9bec1b663f063acb8a8d1984caac9cef8457befe96d4f989abbf0051b0473
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to disposable hosting, forming a link farm, and includes a heuristic for a visual download button lure. The primary URL suggests a lure related to a VPN mod APK, indicating a potential attempt to trick users into downloading malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ketchas.ru/uplcv?utm_term=mango+vpn+mod+apk PDF link annotation
    • http://hondasushi.com/uploads/files/pisano.pdfIn PDF document text
    • http://thestarbusan.com/FileData/ckfinder/files/20210904_7865C5640ED21EC7.pdfIn PDF document text
    • http://hastensandbreakfast.nl/userfiles/file/32482611411.pdfIn PDF document text
    • http://wannawwannie.pl/userfiles/file/ruvojarudatubu.pdfIn PDF document text
    • http://korea-seals.com/ckfinder/userfiles/files/89689590343.pdfIn PDF document text
    • http://globalone-mould.com/gbw/fckfiles/20210906135221.pdfIn PDF document text
    • http://piazzademarini3ge.com/userfiles/files/31698327522.pdfIn PDF document text
    • http://xn--80aiddhbkcq5bcaz.xn--p1ai/upload/files/94279492444.pdfIn PDF document text
    • http://otworz-biuro-podrozy.pl/userfiles/file/12106839551.pdfIn PDF document text
    • http://prograsifkalip.com/files/8292925288.pdfIn PDF document text
    • http://finalbrand.cz/upload/file/tomutuxeronulibelodepige.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/41761249330.pdfIn PDF document text
    • http://www.jamesbgriffinlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132c66b562a3---dewubomojagorekijufuruni.pdfIn PDF document text
    • https://fortworthdental.net/cmsCart/upload/file/39001408062.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/fozajuxurodukifirige.pdfIn PDF document text
    • http://contelex.it/userfiles/files/57880814402.pdfIn PDF document text
    • http://papinchess.ru/userfiles/file/pazarofejevevuwilirutal.pdfIn PDF document text
    • https://paron-rebondir.com/uploads/files/65835082587.pdfIn PDF document text
    • http://lpxs168.com/filespath/files/20210908075908.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/paxitapew.pdfIn PDF document text
    • https://1snrpaulista.com.br/ckfinder/userfiles/files/jutulotasoxit.pdfIn PDF document text
    • http://www.pavimentosyreformasferlu.es/ckfinder/userfiles/files/26373036165.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/dcee3b6777743a1df177abfa4b103e2c/73717346738.pdfIn PDF document text
    • https://svenjakretschmer.com/ckfinder/userfiles/files/zexinafu.pdfIn PDF document text
    • http://astorandblack.net/emailer/userfiles/file/puzesulipiz.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_off0000c242.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC242 10252 bytes
SHA-256: a9a17f92d430b1662ea690c784c49e741e0ae2eb6ff443e61ff184d3810d228a
font_01_sfnt_off0000d901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD901 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f113.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF113 18872 bytes
SHA-256: 3a8d6d8503f1f12863145161b6aeba4396e1d8f5e880f342ac50534bf24c6854