Malicious PDF — malware analysis report

Static analysis result for SHA-256 0ac4d13883c1bc83…

MALICIOUS

PDF

83.0 KB Created: 2021-09-15 11:27:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ab0d1fe290b0dbd6f8912f6ae9d05a0e SHA-1: a02e4f28cdc5a5a6db1a08f70f18dd5f23b2185d SHA-256: 0ac4d13883c1bc83cc9a3fa480c47402e668c25d35c05b470baeae63833ed054
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The presence of embedded JavaScript and a high number of external URLs, many pointing to compromised CMS upload directories, strongly suggests a malicious intent. The ML classifier and ClamAV detection further corroborate this, indicating the PDF is designed to lure users to potentially malicious sites, likely for phishing or to download further payloads. The embedded JavaScript is likely used to facilitate these actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://krisoc.ru/uplcv?utm_term=tell+me+how+i+die+full+movie+free PDF link annotation
    • https://oilbasaro.com/web/images/ckfinder/files/20210901193407.pdfIn PDF document text
    • http://ngoinvest.com/uploads/ckfinder/files/titawevabajitikelajad.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140b9ae6a465---10248601337.pdfIn PDF document text
    • http://pyroglobal.sk/app/webroot/files/userfiles/files/33205809025.pdfIn PDF document text
    • http://ayurveda-shiatsu-nice.com/upload/files/85842295553.pdfIn PDF document text
    • http://sinners-party.de/media/file/vewejajujujeke.pdfIn PDF document text
    • http://thcscatquea.hoaiduc.edu.vn/ckfinder/userfiles/files/35762335066.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614125dd89827---dewesogarolulazeremoriv.pdfIn PDF document text
    • https://riwg.in/userfiles/file/1368564565.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/i12j3cbn7n4gtqc79buc042t3l/wumatosexasonokobirajajum.pdfIn PDF document text
    • https://softwebstar.com/shop/userfiles/file/3009102563.pdfIn PDF document text
    • http://inarchengineering.it/userfiles/files/15546303000.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/rivuxiforuz.pdfIn PDF document text
    • http://slavutich-media.ru/userfiles/file/69424176739.pdfIn PDF document text
    • http://nemeckystrakac.sk/editor_uploads/files/wituwe.pdfIn PDF document text
    • https://evpersoneli.net/ev-personeli/file/22452120777.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/c0ai5drpl3tbar8im4vojbvfrm/xajumo.pdfIn PDF document text
    • http://salwex.hu/file/35612931495.pdfIn PDF document text
    • http://michelesherrinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/19407960637.pdfIn PDF document text
    • http://gaishachuukobuhin.com/js/upload/files/96411811571.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613751a462afa---6542439044.pdfIn PDF document text
    • http://ziva-muzika.cz/files/file/nagupureluref.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16134d93ea8b2d---xowuluzubopig.pdfIn PDF document text
    • https://ctners.com/ckfinder/userfiles/files/78382474854.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/94888279055.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_off0000e2f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F3 16792 bytes
SHA-256: 1b99f87327f29ebae8502b86451df92c2cea0f7a08ea4f474e7bb9e507e7bb5e
font_01_sfnt_off00010e45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E45 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001265c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1265C 10300 bytes
SHA-256: 88d2b078f2a24677e1bc52895c60bb4860e3e99681f4fddb69caec8d46f8d9f8