Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac9b7bd8b0231aff…

MALICIOUS

PDF

70.9 KB Created: 2021-09-03 05:51:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e5ea119256314ae6e89c5422ea7fea9c SHA-1: df25103e4d15b65d6f48ddcb2b62b814b2093a19 SHA-256: ac9b7bd8b0231aff29d628a90c726e09f1c425c498d2f40c71b4df19da0b7482
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for malicious PDFs to execute code or redirect users. Several heuristics indicate the PDF is part of a link farm, with many URLs pointing to compromised WordPress sites or disposable hosting, suggesting an attempt to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089276eec02b---kasagir.pdf In PDF document text
    • http://finalstage.biz/js/upload/files/bimedagomopawobemovo.pdfIn PDF document text
    • https://digireg.at/upload/xiperi.pdfIn PDF document text
    • https://carpanea.it/wp-content/plugins/super-forms/uploads/php/files/b73db7893bdae3cd87852396dfc055b2/kikuxupol.pdfIn PDF document text
    • https://brothers-music.com/ckfinder/userfiles/files/68311500673.pdfIn PDF document text
    • http://megalaserasia.com/upload///26369221444.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/97205599540.pdfIn PDF document text
    • http://zulaikhatextile.com/userfiles/files/zubavodujofapalotavefu.pdfIn PDF document text
    • https://efnnma.org/files/file/livitukatuwekofamaf.pdfIn PDF document text
    • http://www.letnifestiwal.pl/ckfinder/userfiles/files/fexanapumosivedigado.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2c721acbe---xeporipu.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8ed3150409---76562171760.pdfIn PDF document text
    • http://mp-journal.com/media/file/25423523037.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/82891279271.pdfIn PDF document text
    • http://cck-brno.cz/ckfinder/userfiles/files/jazawejuj.pdfIn PDF document text
    • https://tekdalyapi.com/upload/ckfinder/files/41795600595.pdfIn PDF document text
    • http://studiomanzetti.it/userfiles/files/funomotubajapoguba.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/38c52b46a2c286c2868c6e85481f3af8/83914666683.pdfIn PDF document text
    • http://tatishev.ru/admin/ckfinder/userfiles/files/83915043895.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=quantitative+business+analysis+book+pdfPDF 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_off0000b3fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3FB 15852 bytes
SHA-256: 4a01917ed2cd78c144952dd27d46606c21cad26f3b65f3aa43f35a26c42255bb
font_01_sfnt_off0000dc4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC4E 10960 bytes
SHA-256: 582355179fa2afb235a14d4f7135b5f4e281329910e783a98855c1283e5d5091
font_02_sfnt_off0000f5ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1