Malicious PDF — malware analysis report

Static analysis result for SHA-256 28c9f3b99d79d72e…

MALICIOUS

PDF

78.9 KB Created: 2021-09-10 09:08:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 07b624fe9e04f2cf1187bdf8262f2161 SHA-1: 71dc34adef01d8229c132cee77833d8e32bd9d4d SHA-256: 28c9f3b99d79d72e51e912ccc535dee86991b44f847c8a9dc157389834a49c8e
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript, suggesting it may attempt to exploit vulnerabilities or redirect users to malicious sites. The PDF also exhibits characteristics of a link farm, with numerous external URIs pointing to various domains, likely serving as a lure for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://akinmedikal.com/uploads/file/35953795474.pdf In PDF document text
    • https://www.supremecaravans.com.au/application/third_party/ckfinder/userfiles/files/39632168770.pdfIn PDF document text
    • http://kelvista.lt/images/files/28084519579.pdfIn PDF document text
    • http://winso.tw/userfiles/file/risixamewamigajajubibipa.pdfIn PDF document text
    • http://hainescentreasia.com/images/file/58693709928.pdfIn PDF document text
    • https://nhaccugiare24h.com/uploads/userfiles/file/kufiwidolowa.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/e200f1f37746f4fc181f816db5e38e8d/11272971227.pdfIn PDF document text
    • http://flyingwedge.com/uploads/assets/file/dopuker.pdfIn PDF document text
    • https://cyberbirddog.com/userfiles/files/23453800941.pdfIn PDF document text
    • https://huaienclinic.com/uploadpic/files/misitopuxafa.pdfIn PDF document text
    • https://uslugiinzynierskie.eu/eurostyl/photos/file/76948672607.pdfIn PDF document text
    • http://lev-steklo.ru/userfiles/file/44502325605.pdfIn PDF document text
    • https://malmospelmanslag.se/userfiles/file/tekezudefasi.pdfIn PDF document text
    • http://scuolascifondocortinadolomiti.it/userfiles/files/96144821272.pdfIn PDF document text
    • http://gz-chengeng.com/uploadfile/files/33409799195.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210907094908946.pdfIn PDF document text
    • http://thewellmanteam.com/userfiles/files/fijuvuduvofijabome.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/vadim.pdfIn PDF document text
    • http://mjacz.cz/soubory/files/warasiguvewujuja.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/161344bfac729b---85339313520.pdfIn PDF document text
    • http://studiolorenzoni.eu/userfiles/files/75363267433.pdfIn PDF document text
    • http://cathyourhair.nl/js/ckfinder/userfiles/files/vaxutuwuseripumimumuvonup.pdfIn PDF document text
    • http://print-printonline.com/ckfinder/userfiles/files/75310323412.pdfIn PDF document text
    • https://asharfilalkulfi.com/ckfinder/userfiles/files/43903568300.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=subway+princess+apk+modPDF 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_off0000cf5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF5B 11136 bytes
SHA-256: fc50cd74eac0bdbbe7de8788da3092f21b60995ed8e27319be304fa87b8f5da6
font_01_sfnt_off0000e922.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE922 17236 bytes
SHA-256: 2157ba3a0d56a61c3a890972824a6ad11d2608064a6a1dff0572e84f4ed4bfb9
font_02_sfnt_off000115e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1