Malicious PDF — malware analysis report

Static analysis result for SHA-256 436e328dc6d0d46e…

MALICIOUS

PDF

75.9 KB Created: 2021-10-07 16:44:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: a7f5bc323ae2d8f33fc081d8cde1c4a9 SHA-1: b65c3511a7933324517065ef57cfcf5090f8ecb6 SHA-256: 436e328dc6d0d46e2349ce8027b7a9c57f9d4dac1224151a156c34ef02105201
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with heuristics indicating embedded JavaScript and external URIs. The PDF contains numerous links to disposable domains, suggesting a link farm or phishing lure. The embedded JavaScript likely facilitates the redirection to these external sites, which are often used to host further malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://garglob.ru/uplcv?utm_term=c%2B%2B+compile+with+header+files PDF link annotation
    • http://artgraf24.pl/userfiles/file/57608065221.pdfIn PDF document text
    • https://jnvhardoi.org/ckfinder/userfiles/files/fejudol.pdfIn PDF document text
    • http://immobiliareborghi.com/userfiles/files/2349627336.pdfIn PDF document text
    • http://irvine.songhakbbq.com/uploads/files/69879615865.pdfIn PDF document text
    • http://terrietanaka.com/library/files/fidofokipofumu.pdfIn PDF document text
    • https://warungmimpishio2.com/contents/files/45829323521.pdfIn PDF document text
    • http://hublihorse.com/uploads/userfiles/files/perulepojirafaroburavem.pdfIn PDF document text
    • http://xueyuan.zlyxgw.com/uploads/ckeditor/files/20210930190045.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/161466c8e42267---43625666059.pdfIn PDF document text
    • http://dhalahoredeals.com/survey/userfiles/files/polur.pdfIn PDF document text
    • https://newchat.xyz/js/ckfinder/userfiles/files/sozefelemit.pdfIn PDF document text
    • http://finpacecuador.com/userfiles/file/99243617918.pdfIn PDF document text
    • http://comitatoamiantovelodromo.org/userfiles/file/68627845122.pdfIn PDF document text
    • https://hondamienbac.vn/userfiles/file/gilozebokege.pdfIn PDF document text
    • https://ms1oke.com/contents/files/2886746103.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/16158fb97e92f6---9568524689.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/60269008254.pdfIn PDF document text
    • https://apskarota.org/userfiles/file/11326854516.pdfIn PDF document text
    • http://starwindows.ie/ckfinder/userfiles/files/70165315086.pdfIn PDF document text
    • https://sleepthai.com/piceditor/file/vigidudanobatugadofikub.pdfIn PDF document text
    • https://jatransfer.com/userfiles/file/94731906023.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/viviwo.pdfIn PDF document text
    • http://wakabaeducation.com/userfiles/file/58918932832.pdfIn PDF document text
    • http://thuocamakong.net/userfiles/image/file/tozematufomosuguvitif.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1615745bd220f7---47793703366.pdfIn PDF document text
    • https://zd-zeta.com/uploads/files/202109080244235362.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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c45f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC45F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC71 17168 bytes
SHA-256: 32bc25c2b996407c3695c4541ef14ffd6e29f0574c9893a1763f3bc19f2c4838
font_02_sfnt_off000108e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E4 10900 bytes
SHA-256: b052b20a566791effc3b5036eef9c513bd6f456f4af3065e3d04319d73ab82a1