Malicious PDF — malware analysis report

Static analysis result for SHA-256 903ac4edb4aeb3ac…

MALICIOUS

PDF

84.1 KB Created: 2021-07-30 06:35:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8cbd8c41b6cc17268ca397f2016bd568 SHA-1: 4067548c5558cc1d81e913597e924e0c6a1144e3 SHA-256: 903ac4edb4aeb3ac14ec46484db4319402bef6888ca717a7844aca1309111d44
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous links pointing to compromised WordPress sites and disposable domains, suggesting an attempt to distribute malware. The heuristic firings indicate a link farm designed to trick users into downloading files, consistent with phishing or malware distribution campaigns. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://nextgt.eu/uploads/file/19913618141.pdf In PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608a8006d605a---12510308427.pdfIn PDF document text
    • http://szyldkj.com/luodan/images/userfiles/file/gimabuletonu.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2d79e21b7---78425266449.pdfIn PDF document text
    • http://cedarvalekansas.com/clients/875954/File/46362481771.pdfIn PDF document text
    • http://stroi-sistema.ru/img/japewo.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/gv1nt5fso6n8d5s2vb71k1s7ah/ludopijomonitowupoj.pdfIn PDF document text
    • https://ebdaatcoop.com/userfiles/files/wutijudafaga.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a8718f02549---92982507940.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c85064695---bunufusodupuzodazarufeg.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607de91e4d1a3---vifuxerofamux.pdfIn PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/75618030179.pdfIn PDF document text
    • http://year-c.com/upload_fck/file/2021-7-4/20210704181115278218.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608002b5aa32d---4097264229.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160845d8434292---nofefaxafujaxazineliwo.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/5aa02dcacdab89d599a46a6a73d07f2f/kixexipo.pdfIn PDF document text
    • https://alajuusa.eemedia/contents/file/ritanusenasumodazog.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160d4813d68b91---4966399470.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/12789956996.pdfIn PDF document text
    • http://kolesnikov.pro/ckfinder/userfiles/files/nesubijadakivodop.pdfIn PDF document text
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/gunajutojilozomi.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/8b0830c2b656d832a0a28706bcb770f6/gedara.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/12192a5b57f9b1300564bd62653c43b3/mifajanafo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=descargar+sonic+classic+heroes+para+android+apkPDF 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_off0000e4b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4B3 17980 bytes
SHA-256: 1630ba50812b99a7b6d5383affc15cea41561abc4a5cb4820e33e35b5072b98a
font_01_sfnt_off00011261.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11261 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012a78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A78 10788 bytes
SHA-256: 9695e7fa33c86f4b60d44bfa1b6fb37eb424836e82a744a2873d9ec565113eae