Malicious PDF — malware analysis report

Static analysis result for SHA-256 681000bc35c7add7…

MALICIOUS

PDF

73.2 KB Created: 2021-09-10 10:01:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 56465be545b15d991544031e4913258d SHA-1: ba183b58aa4ba242e8c979284a2adbf2e986d3df SHA-256: 681000bc35c7add77ca15effe284f2e088b4a58406c5cb5881350b954eb17ffe
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple distinct hosts, some of which are identified as compromised CMS uploads, suggesting an attempt to obscure the final destination or leverage compromised infrastructure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://akvaguru.hu/user/file/fugubeba.pdf In PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135b9295dbeb---59608287549.pdfIn PDF document text
    • https://www.newhorizonscrisiscenter.org/ckfinder/userfiles/files/rogoxejow.pdfIn PDF document text
    • https://magnanerie-cazilhac.com/userfiles/file/1647143996.pdfIn PDF document text
    • http://mega.kz/media/upload/files/16112434401.pdfIn PDF document text
    • http://anindecor.pl/files/file/55354127515.pdfIn PDF document text
    • https://citronel.com/userfiles/files/jenituxafopujewumu.pdfIn PDF document text
    • http://www.deopendeur.org/imgUser/file/gusaworoxijazosixoxobemo.pdfIn PDF document text
    • https://tauthuy.vn/upload/files/lurasapexotisag.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/161375a54a6563---88565421105.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/31231300673.pdfIn PDF document text
    • http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/14878591960.pdfIn PDF document text
    • https://angkalaris.com/contents/files/12962400675.pdfIn PDF document text
    • http://carscaso.com/js/upload/files/jaluxefetozawagawupi.pdfIn PDF document text
    • https://parlagame.com/calisma2/files/uploads/lipogifase.pdfIn PDF document text
    • https://hankilfood.com/upfile/files/46352894033.pdfIn PDF document text
    • http://veszpremlizards.hu/_user/file/91560046620.pdfIn PDF document text
    • http://xn--9i1b14lwsg1seumdzsx.com/upload/fckeditor/file/tuwulogavif.pdfIn PDF document text
    • http://www.bongbansaigon.com/uploads/files/103901504.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613991d5be328---seladotoratotifimu.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/malogaduboxajipemew.pdfIn PDF document text
    • http://singer-island-condos.com/userfiles/files/63538591834.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=la+muerte+y+otras+sorpresas+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_off0000b93c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB93C 18000 bytes
SHA-256: b8fbc44509427ac0ed986fe4aaf1319e1170e902e10a7e4fd3a0ced291e69a87
font_01_sfnt_off0000e6df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6DF 10588 bytes
SHA-256: c2d40e558017302078decdd2aade42964810fb711b0d2900b3cdc3b2af5b46ec
font_02_sfnt_off0000ff1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1