Malicious PDF — malware analysis report

Static analysis result for SHA-256 0cf9da01b3266787…

MALICIOUS

PDF

80.6 KB Created: 2020-06-12 17:45:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: 03a6fb0e2ce6946c36919230b0c09180 SHA-1: 8f6c9438f01f1a1dcac7e262bf0ac0e8b058856a SHA-256: 0cf9da01b32667879a60b5aab147685a09c228948de9184b95e84ad2f35ce621
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of embedded external links to other PDF files hosted across numerous domains. This behavior is indicative of a link farm or SEO manipulation scheme, which can be used to distribute malware or phishing content. The ML classifier strongly flagged this PDF as malicious, supporting the suspicious nature of the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 4

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jinfuzaixianyouxi.br3h.com/uploads/1/3/1/6/131637103/131637103.html#%25D9%2582%25D8%25B5%25D8%25B5+%25D8%25AC%25D9%2586%25D8%25B3+%25D8%25A7%25D9%2584%25D8%25B4%25D9%2588%25D8%25A7%25D8%25B0+%25D8%25A7%25D9%2584%25D8%25B4%25D8%25A8%25D8%25A7%25D8%25A8 PDF link annotation
    • http://passion4mission.com/uploads/1/3/0/9/130969368/3c10755.pdfIn PDF document text
    • http://webmaster.no-classics.de/uploads/1/3/0/7/130738680/wepixuja-wogusix.pdfIn PDF document text
    • http://aiasciencemagazine.com/uploads/1/3/0/6/130622022/9296401.pdfIn PDF document text
    • http://74-123-77-101.mgwnet.com/uploads/1/3/0/4/130489262/fegofo-lolupunuzugita-refuge.pdfIn PDF document text
    • http://server.viewourbenefits.com/uploads/1/3/0/2/130289625/mubufigafowidek_rowewuloso_nevorixujifuja_nonefuw.pdfIn PDF document text
    • http://manosunidasac.com/uploads/1/3/1/6/131606420/kobik-rokiximetip-doforow.pdfIn PDF document text
    • http://webdisk.cbdiai.org/uploads/1/3/2/3/132303382/6322205.pdfIn PDF document text
    • http://hostmaster.obsthof-kotulla.de/uploads/1/3/1/6/131637095/mopexiv.pdfIn PDF document text
    • http://letstalkcnas.com/uploads/1/3/0/8/130814279/744832.pdfIn PDF document text
    • http://crossfoodbank.org/uploads/1/3/0/9/130969536/nalage-kiwisipiwenirif-vevalixado.pdfIn PDF document text
    • http://serenityskinexperts.com/uploads/1/3/0/9/130969726/velejerud-kefusofavubur-fadukuritabuj.pdfIn PDF document text
    • http://theaddcouple.com/uploads/1/3/1/4/131453871/sezox.pdfIn PDF document text
    • http://hfes2019.org/uploads/1/3/0/5/130538995/055b547c1a8670.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://metazak.files.wordpress.com/2020/06/ximugixoxibelinedonu.pdfIn PDF document text
    • https://xidufunamopa.files.wordpress.com/2020/06/dadewomorerizopav.pdfIn PDF document text
    • https://wizuvife.files.wordpress.com/2020/06/20038919835.pdfIn PDF document text
    • https://sivemaga.files.wordpress.com/2020/06/wapuxoput.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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off0000d609.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xD609 33596 bytes
SHA-256: bbb0decfed766858a1bb2e0cafdeff6d7dcf6d88e20666b28b42dc6a51fc378e
font_01_sfnt_off00011046.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11046 10420 bytes
SHA-256: cd58c94ef41cab2cfbad57d40bd864a60dff9eeeecd5c8b0d1066c579ec1a3f5