Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c89a221a7dffe4b…

MALICIOUS

PDF

82.4 KB Created: 2021-09-13 06:30:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: aa21dea1d1df0d011ff6eae21a38e11e SHA-1: e3818286e05c459ac93ffc1440c29d1a158038e8 SHA-256: 6c89a221a7dffe4ba4c753125e9ebf8b48a1a7d161a0cbf3e47e60d40f2a0f46
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, hosting numerous external URLs on disposable domains, with one URL specifically mentioning 'instagram 500 followers increase' suggesting a lure. The presence of embedded JavaScript, though not detailed here, is a common technique for exploiting PDF vulnerabilities or redirecting users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://infrive.ru/uplcv?utm_term=instagram+500+followers+increase PDF link annotation
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/16137b7da9ae5d---65534756490.pdfIn PDF document text
    • https://irantruck.ir/data/file/21513591990.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/52809548348.pdfIn PDF document text
    • http://bilateralmatters.org/userfiles/file/68081671844.pdfIn PDF document text
    • https://aquarell.ro/userfiles/file/83049490005.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/30913300579.pdfIn PDF document text
    • https://www.caissedesecolesdu5eme.fr/backoffice/ckfinder/userfiles/files/86111762789.pdfIn PDF document text
    • http://vnndt.com/Images_upload/files/zemifakefogoji.pdfIn PDF document text
    • http://askort.pl/Upload/file/kotunupukapoxuv.pdfIn PDF document text
    • http://serramentisiciliano.it/userfiles/files/zaxudixux.pdfIn PDF document text
    • http://bixenony.com/userfiles/files/38073728648.pdfIn PDF document text
    • http://colokit.thienlonggroup.com/Images_upload/files/beziruwifowes.pdfIn PDF document text
    • https://www.institutvzdelavani.cz/files/nikeduguwepetoruw.pdfIn PDF document text
    • https://artbynela.com/uploads/file/61698380975.pdfIn PDF document text
    • https://www.asoriofrio.org/ckfinder/userfiles/files/mejolagopivofodebazu.pdfIn PDF document text
    • http://kanchanaspa.com/ckfinder/userfiles/files/sepaduzunezuki.pdfIn PDF document text
    • https://mimpishio.com/contents/files/sulufazesomofanizulifovos.pdfIn PDF document text
    • https://beytarimcilik.com/admin/editor_resim/file/23313602959.pdfIn PDF document text
    • https://vzglavniki.net/data/file/tifiloxevatemanitela.pdfIn PDF document text
    • https://www.mftelhas.com.br/adm/Editor/ckfinder/userfiles/files/dukolaxazekosodejel.pdfIn PDF document text
    • https://ardiinerkh.mn/uploads/userfiles/files/wosus.pdfIn PDF document text
    • https://mediaget.ru/userfiles/files/16066521129.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/31484935711.pdfIn PDF document text
    • https://pcparts.fr/ckfinder/userfiles/files/nikidelawonasewosexep.pdfIn PDF document text
    • http://kingsap.com/file_media/file_image/file/luxajisi.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_off0000dd94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD94 17372 bytes
SHA-256: d3b7a2e72d0cb9f9aab904f61bc23a3971438a1ddf8cbac50f1ed48e3ccbfbb0
font_01_sfnt_off00010ab2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122C9 10972 bytes
SHA-256: a50bcc12d72a692bb485a931421d93b5313c6e072b01e875c879550ddad69db2