Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd31a91763cd3e76…

MALICIOUS

PDF

84.8 KB Created: 2021-06-29 02:27:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: e8f0f258ee150dabc2fb36059402a7c0 SHA-1: a44b30d185cf81c7fcf985010780cf348c6e9bf1 SHA-256: bd31a91763cd3e76e21bfab69a98a78e00024720436318e77059d067aa2b7dda
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a link farm directing users to multiple external URLs, with several hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lead users to phishing or malware download sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting a deliberate effort to obscure the true destination through numerous disposable links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 6

  • 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.
  • 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://eatorhours.org/e-bussiness/fckimages/file/gumip.pdf In PDF document text
    • http://ottotech.center/userfiles/file/xitisutegerusitobofogo.pdfIn PDF document text
    • http://razaviota.ir/basefile/razaviotair/files/sebemefasonujazulogu.pdfIn PDF document text
    • http://lblussana.it/images/file/66155886731.pdfIn PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/6f40d2ded26398c861dbbb7b194bc12c/fabukuwufitobejezarez.pdfIn PDF document text
    • http://randoquad72.fr/userfiles/file/59047560304.pdfIn PDF document text
    • http://upoart.com/ckfinder/userfiles/files/36270104949.pdfIn PDF document text
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/4ea2823fbc4a1ec7690c4ca35b1b3f04/76859647998.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/4c1f073b0e8887977785fca0207c0680/woxofebiderabavepaf.pdfIn PDF document text
    • http://modamoda.nl/uploads/pic_lib/file/zodekome.pdfIn PDF document text
    • http://stepasidemedical.com/images/uploads/file/woxogiwidu.pdfIn PDF document text
    • https://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/hdfracok43j8joeiv0mf3421rm/matomaferijobuwamivuz.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/bowutosip.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/5b4dd20449f05ceb86d24183dbd4631b/6030926936.pdfIn PDF document text
    • https://hotnews.md/upload/userfiles/files/xipojux.pdfIn PDF document text
    • http://prestopc.it/upload/file/wamuras.pdfIn PDF document text
    • http://imhkayseri.com/resimler/files/jegopitifem.pdfIn PDF document text
    • http://taiyoaquris.cn/upload/userfiles/files/20210605133350.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/82asttrojfi9k1h8eau9ep8or6/25598272666.pdfIn PDF document text
    • http://thaihotelsale.com/FileData/ckfinder/files/20210629_931AFCDCA5EE95E3.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=question+bank+on+agriculture+for+competitive+examsPDF 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_off0000e7a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ffb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFB8 16752 bytes
SHA-256: 1b6ac9506521f1ebdf97ac30e3b33725042bb635ce170b20802188b8a39e4db7
font_02_sfnt_off00012b60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B60 11384 bytes
SHA-256: 0fde6acf80053f0c70271fe87bb8d72ac5817a38964540d3b6f7dd54e49af009