Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1231ea783ebe3e3…

MALICIOUS

PDF

70.3 KB Created: 2021-09-25 23:16:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 377d146782316c20ca51e0fb20d345a2 SHA-1: 3a65ab3671e161fdd3dacb213e286c23afb504d3 SHA-256: f1231ea783ebe3e31105e654db221333e947649b9d7797ccf51b072e27e4b3f9
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier. It contains embedded JavaScript and a large number of external URIs, many pointing to disposable domains, indicating a link farm or phishing operation. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting the document is designed for SEO manipulation or to distribute malicious content via numerous links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://www.mustwalge.ee/data/content/files/30483831229.pdf In PDF document text
    • http://geomanteia.com/userfiles/files/68884696780.pdfIn PDF document text
    • http://lab4050.com/upload/editor/file/tefojinepudozofemudab.pdfIn PDF document text
    • https://jmcoverseaspvtltd.com/uploads/files/10524824151.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/21dff51ce7dde0192789b1326bd16b23/69092358256.pdfIn PDF document text
    • http://galenbio.com/images/upload/file/bisifizuda.pdfIn PDF document text
    • http://zenobiacultura.it/userfiles/file///niboki.pdfIn PDF document text
    • http://hasekei.jp/userfiles/file/daseresagumitevoximizi.pdfIn PDF document text
    • http://gonzagafood.com/userfiles/files/kanevoxabowo.pdfIn PDF document text
    • http://synhbio.com/upload/files/5684253645.pdfIn PDF document text
    • http://rtm-plus.ru/ckfinder/userfiles/files/33246177453.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/ae03a870fa4846222e2661a56e99bcf0/veridugasut.pdfIn PDF document text
    • https://fitness-sport.it/userfiles/file/1983626840.pdfIn PDF document text
    • https://www.auto-ecole-acm.com/ckfinder/userfiles/files/93129522081.pdfIn PDF document text
    • http://tufaghanafc.com/js/ckfinder/userfiles/files/gesadis.pdfIn PDF document text
    • https://biserica-izvorul-tamaduirii.ro/files/furibes.pdfIn PDF document text
    • http://goodfortune.hk/UpLoadFile/file///bejokam.pdfIn PDF document text
    • https://lesura.net/userfiles/file/jijuxefufinime.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/23882832252.pdfIn PDF document text
    • http://sushiloverca.com/uploads/files/vikeruwitokavogatexi.pdfIn PDF document text
    • http://panhongbo.com/ckfinder/userfiles/site_eachfun_com/files/vudazorisegotikelemidor.pdfIn PDF document text
    • http://beming.com/ressource/site-image/files/pituladotazu.pdfIn PDF document text
    • https://maxflowfans.com/userfiles/file/39513687916.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/6602503084.pdfIn PDF document text
    • https://ginniglobal.com/uploads/file/kinawesi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=vidmate+apk+app+installPDF link annotation
    • 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_off0000b163.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB163 16780 bytes
SHA-256: 99cfe0b523e7393ece2199677d3459a68ca8bdb5a6c60533be3cb5c85fa00383
font_01_sfnt_off0000dc76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC76 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f48d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF48D 10396 bytes
SHA-256: 9b8314fa404866fa169c338b4bb17ab340c38c703852fd2d4cdd4176ca9390cf