Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91f820c2df55f39…

MALICIOUS

PDF

83.4 KB Created: 2021-09-24 00:05:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: ace948726c7f0ddfbfdeb8e39dc612bc SHA-1: 1e8b1cad0f197f3c3dfc0bed696fd3458c35b136 SHA-256: c91f820c2df55f3953b0afe886baf777c6a666df32cf9e6497c2048f141e2ac3
134 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. The presence of numerous external URIs, many pointing to disposable domains and forming a link farm, suggests an attempt to redirect users to malicious content or phishing sites. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • 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 http://a-xian-coat.com/uploads/files/202109130738307980.pdf In PDF document text
    • http://jcon-aps.dk/userfiles/file/zijer.pdfIn PDF document text
    • http://fitviewer.de/files/file/fufekadasefofot.pdfIn PDF document text
    • http://blackivy.pl/userfiles/file/21840861942.pdfIn PDF document text
    • http://kuryakyn.ru/userfiles/file/muzuzuxu.pdfIn PDF document text
    • https://easternresources.net/ckfinder/userfiles/files/22072071418.pdfIn PDF document text
    • http://lifecontinues.ru/images/files/94284002680.pdfIn PDF document text
    • http://caycanh.vn/images/fck/file/mokibupavolakiwaz.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/24365684688.pdfIn PDF document text
    • https://coverline.ro/userfiles/file/gumufovi.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/wifutafomiri.pdfIn PDF document text
    • http://docando.es/js/ckfinder/userfiles/files/birigogaruropufuritefa.pdfIn PDF document text
    • http://nasledie-sluck.by/var/upload/file/30545673490.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/f9igichknj9scqpdtdkf3qarcf/15035442732.pdfIn PDF document text
    • https://szallas-karpatalja.net/upload/kanuginap.pdfIn PDF document text
    • https://hyosung-gulf.com/uploads/file/xitunumawekuvakanafemi.pdfIn PDF document text
    • http://delfosventures.eu/userfiles/files/wiforubodaba.pdfIn PDF document text
    • http://cantinachitarra.it/userfiles/file/galumavetesalupexazaxe.pdfIn PDF document text
    • https://xn--80apefbdm9ah5g.xn--p1ai/userfiles/wisebinetavawo.pdfIn PDF document text
    • https://selapro.com.au/application/third_party/ckfinder/userfiles/files/31687365098.pdfIn PDF document text
    • http://montpellier-business-plan.fr/mbp/upload/images/images/upload/ckfinder/nipamatonelofiwo.pdfIn PDF document text
    • http://www.pes.edu.mn/ckfinder/userfiles/files/bokunefijawet.pdfIn PDF document text
    • https://mailing.crpm.ch/ck/ckfinder/userfiles/files/66434837401.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/brg6iv0km592knie9s9aerdtj7/76244343984.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=siswati+short+stories+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_off0000e249.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE249 17632 bytes
SHA-256: 366692b2d25ce74e67a5963b5906e03b6acecd87cc9e0ca03af7d619c811d5ec
font_01_sfnt_off00010fab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FAB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000127c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127C2 10604 bytes
SHA-256: 5817b7a3b05a76885ebf7551466bdd3a348580a93cf8ea7269ee13d808b50bc7