Malicious PDF — malware analysis report

Static analysis result for SHA-256 153cdc4bca715920…

MALICIOUS

PDF

75.6 KB Created: 2021-07-12 22:16:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fdc83b7a57717844a3eae649de8d5381 SHA-1: 21ec4ed0347ab52bcf13946900b45bfd3849cd76 SHA-256: 153cdc4bca7159205b8bfbb00771dbe97b76a54257376afeeb32ae182f000079
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. It also features a link farm pointing to numerous PDF files hosted on various domains, suggesting an attempt to obscure the ultimate destination or to distribute a payload. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://fenotropil.ru/userfiles/file/sokutivuwukokifufak.pdf
    • http://tsutae-f.com/js/upload/files/75664762730.pdf
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608636e854f29---2008128147.pdf
    • http://hysansam.com/fckeditor/userfiles/image/tumudomugipesuvafeninapo.pdf
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/83cbgb8j4saa18lpcqu6id7eg6/xuneko.pdf
    • https://alutat.com/data/file/juzutazaka.pdf
    • https://alexandrapanayotou.com/web/images/static/file/gixobipodogik.pdf
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/ecae36595297f9164527addc92fc1958/xupunazuwiwudoxirusaxo.pdf
    • http://alexanderjamesbackcatalogue.com/userfiles/file/komajuna.pdf
    • http://makingtheturngolf.com/clients/9/92/925d9bae4ecf380f28dbe0e1390c16eb/File/46177586881.pdf
    • http://tfh-filter.hu/_user/file/91113830425.pdf
    • http://shs1977reunion.com/clients/41590/File/60613243864.pdf
    • https://qnzar.com/files/24231076058.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16071c1e7d5958---69529972951.pdf
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/rovepopoxa.pdf
    • http://jakebenmd.com/clients/0/0e/0eef9d569b11303d075d19626cc6f958/File/dovenugifalinikixataduw.pdf
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085685ca260b---70997046239.pdf
    • http://bezagsecurity.cz/userfiles/fuxutomaxoko.pdf
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160767de98da19---rovitoranimevixegikovat.pdf
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ced94c48d28---zavomutifanewatupagaw.pdf
    • http://asea-admin.com/_userfiles/file/20210606120511.pdf
    • http://firewheels.pe/userfiles/file/minumisewevamoti.pdf
    • https://jodhpurtravels.com/nbloom/fckuploads/file/12366898947.pdf
    • http://hanboo.cn/Uploads/file/2021052018260270554.pdf
    • https://bbpartner.cz/userfiles/file/52724632600.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=moy+medical+centre
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c5b4.bin
fab345a54e15e762acde8b11a5318019de54eafd6d4d48bea25cfafc3f117f1e
pdf-font-stream PDF embedded font (sfnt) at offset 0xC5B4 10468 bytes
font_01_sfnt_off0000dd73.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD73 16792 bytes
font_02_sfnt_off0000f585.bin
6703d4d7bc84d7377474bf216d889cb085d4bd50471978972c59b30793c88325
pdf-font-stream PDF embedded font (sfnt) at offset 0xF585 16728 bytes