Malicious PDF — malware analysis report

Static analysis result for SHA-256 8133431c24d44477…

MALICIOUS

PDF

103.3 KB Created: 2021-06-29 10:37:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: b2d6fde7cd7755f4e4ce6a82cd187c2b SHA-1: e327267e5f081ebf5802191765b7ba05dd22b5ca SHA-256: 8133431c24d44477e25bea7f9234ab1848d574b767b16e87cdff2171d3ada3a0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, a common technique for executing malicious code within PDFs. It also features a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites, suggesting an attempt to obscure the final destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/mtd5hcudff79p2hr4p0b071jo1/telopebuwuwozolumaxozevut.pdf In PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/bc2ffac4bbc27ba771b9d4fae9dab861/kezewazixuputovibekul.pdfIn PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cda97acd28---viwosinipu.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f79fddc6a7---vokuvu.pdfIn PDF document text
    • http://cocoal.com/uploads/file/jusowanivofevika.pdfIn PDF document text
    • https://www.kcequipment.com.au/wp-content/plugins/super-forms/uploads/php/files/2bf210c38ec9041466af5da4bb9acaf9/7703620393.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c3a0df2319f---sijubefa.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/5d3d235e4975bbd58e44dc506f308804/34633272777.pdfIn PDF document text
    • http://amandatour.ru/js/ckfinder/userfiles/files/60506680239.pdfIn PDF document text
    • https://etre-cheval.fr/Applications/MAMP/htdocs/etre%20cheval/news_pix/file/8559962926.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/1e0958b066cfdcd28f749c88d2e9464f/zakixaligipatufenolapefob.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5c375f0340---14423094592.pdfIn PDF document text
    • http://clubselectionvoyages.com/images/file/27400653914.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/tbcfogof9kfsl8njnleun0r8m1/90623864768.pdfIn PDF document text
    • http://shannonlakeestates.org/fck_images/file/pumunawanadovu.pdfIn PDF document text
    • http://pdww.ru/ckfinder/userfiles/files/22772697884.pdfIn PDF document text
    • http://selfmadefilms.nl/userfiles/files/zevid.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082cd460dfc8---nenalawi.pdfIn PDF document text
    • https://gilbertems.com/videos/file/lesaxo.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c54d88affd2---28969670601.pdfIn PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a2655539a64---kasizofitixatijo.pdfIn PDF document text
    • https://senhewood.com/d/files/16639312489.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=long+riddles+with+answersPDF 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_off00013468.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13468 16780 bytes
SHA-256: 635d0a11d468e38cd63eb8dfc1673852796c15503d18cbf4da9e342ecf1362e0
font_01_sfnt_off0001601b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1601B 10572 bytes
SHA-256: 8c9658d76b3cffc7541fa4f847eee3ff9302b0862d1f6d6091b4107b0a022184
font_02_sfnt_off00017801.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17801 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1