Malicious PDF — malware analysis report

Static analysis result for SHA-256 885485ce1b0948f0…

MALICIOUS

PDF

82.5 KB Created: 2021-09-22 22:56:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1bf76db008af7bff8d1df52734eaa87d SHA-1: 7f97c67483c80de4fd1883db3d2606f3aa83dc3e SHA-256: 885485ce1b0948f040b88aebf962f93f4679494fda4c4262a99917bd4a972f4b
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. This script likely redirects the user to a link farm, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the numerous external URLs found. The ClamAV detection and ML classifier further confirm the malicious nature of the file, suggesting it's part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://slkuang.com/v15/Upload/file/2021918104233419.pdf In PDF document text
    • https://gadd-asso.org/userfiles/file/81206379570.pdfIn PDF document text
    • http://xn----otbb6ahq3d.xn--p1ai/ckfinder/userfiles/files/95791203085.pdfIn PDF document text
    • http://snsi.jp/image/news_file/batizexa.pdfIn PDF document text
    • http://cnhhgj.com/upfiles/userfiles/file/wamafamonodovikeme.pdfIn PDF document text
    • http://www.sctiec.com/up_files/FCK/file/kilepepokaw.pdfIn PDF document text
    • https://copab.tn/216mag.svn/uploads/files/dajisefelexiv.pdfIn PDF document text
    • http://195exim.com/datas/files/68469233908.pdfIn PDF document text
    • http://kommunikator.nu/demo/userfiles/file///97887179149.pdfIn PDF document text
    • http://pomocnaukowa.net/Upload/file/sunirax.pdfIn PDF document text
    • http://www.iece.in/userfiles/file/82578070471.pdfIn PDF document text
    • http://klpa.net/userData/board/file/53564593230.pdfIn PDF document text
    • http://smenergy.kr/uploaded/file/9741856826136bca100f95.pdfIn PDF document text
    • http://hzxf.com/images/upload/File/11791471193.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/vuwiwefozodedivugol.pdfIn PDF document text
    • http://soles2walk.cz/data/file/mowodovurawamivexetorole.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/10322262963.pdfIn PDF document text
    • http://pazzo.jp/js/upload/files/87816104320.pdfIn PDF document text
    • https://fo-prefectures.com/pages/files/kovawotiburemazu.pdfIn PDF document text
    • http://cokhivietuc.webthoidai.com/img-vietuc/files/pizixojefogubegok.pdfIn PDF document text
    • http://yasairamenbar.com/uploads/files/xomopixakawune.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/44o51tkg0tfp6dt7nch6r56na5/68625220803.pdfIn PDF document text
    • http://kraemer-duennebacke.de/files/file/86673301990.pdfIn PDF document text
    • http://fitsiluet.cz/data/file/82899301562.pdfIn PDF document text
    • http://xn--80ab1a9a.xn--p1ai/sadm_files/farujo.pdfIn PDF document text
    • https://resulgame.com/calisma2/files/uploads/2503809541.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=structure+and+interpretation+of+computer+programs+second+edition+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_off0000de36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE36 16892 bytes
SHA-256: bcddea28f2e5037d9834067e01f45a9f1a9733a19579bc7d32b926a52e10f33c
font_01_sfnt_off000109e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109E8 11092 bytes
SHA-256: 261863e43eb61ba2866527a5c3723a8f86df608dda239a99cbb055155fcd77a6
font_02_sfnt_off00012385.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12385 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1