Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b5ec3655ce81871…

MALICIOUS

PDF

81.3 KB Created: 2021-09-13 14:50:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 3a130c392d2c41e39ce7389c8a024b11 SHA-1: f8a6b80774345c2b1b6c7c8b2e0c28b32096df75 SHA-256: 3b5ec3655ce81871907f4f1189d61bd8f66ecbb035bb01aff9cea124a4a3cc23
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external files, many hosted on disposable domains, suggesting a link farm designed to distribute malware. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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.
  • 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://envigest.cz/upload/file/95563457048.pdf In PDF document text
    • https://comobrew.com/newsite/images/user_uploads/file/17562733043.pdfIn PDF document text
    • http://bloodfaces.de/attachment/file/derigumagebefuxabo.pdfIn PDF document text
    • http://xn--zb0bw3kv4s8mn.com/upload/fckeditor/file/39012062080.pdfIn PDF document text
    • http://msmzizkov.cz/data/dokumenty/kugevotozafotimabevomow.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/q1dnes974hoav1s415kc1gu9hm/mufigoporubegofid.pdfIn PDF document text
    • http://annabarons.lv/files/files/86270963861.pdfIn PDF document text
    • http://unibox.lv/files/text/wovakaseneruv.pdfIn PDF document text
    • http://purepoem.com/resource/docContentImg/file/2021-09-04/0b070d66f20eb5f3ab9d371a12b50fef.pdfIn PDF document text
    • https://atlaskvartir.ua/data/uploads/files/juwigopidilotek.pdfIn PDF document text
    • http://3sdent.com/upload/files/kejekijin.pdfIn PDF document text
    • http://lamelove-zakryti.cz/userfiles/file/pogixurunapefopuzalelo.pdfIn PDF document text
    • http://gerocuki.hu/user/file/69299741934.pdfIn PDF document text
    • https://ikorti-iao.com/userfiles/files/84442565367.pdfIn PDF document text
    • https://xn--psg-9lac.hu/files/files/79557891664.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/3b59b2c3e7b424ea6d6825261d5a8f9e/sobixorepazilovofi.pdfIn PDF document text
    • http://koutingchina.com/upload/files/tupobaluvejuvokejuxet.pdfIn PDF document text
    • https://ckeditor.pamlskovnik.cz/ckfinder/userfiles/files/58988888269.pdfIn PDF document text
    • https://clifestyle.net/uploades/userfiles/file/jisupuwudivi.pdfIn PDF document text
    • https://htlexpress.com/ckfinder/userfiles/files/povunajuxagefagibokixa.pdfIn PDF document text
    • https://www.hosotte.com/ckfinder/userfiles/files/ludegukof.pdfIn PDF document text
    • http://issaproject.com/app/views/panel/ckfinder/userfiles/files/59501580674.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=gta+v+android+download+linkPDF link annotation
    • https://lapdonline.org/file/juzirikoxajarumaxaj.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_off0000dac0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAC0 10224 bytes
SHA-256: 837056e76801d976fe45a61577f73af198264cda92c034515e1cc2ab3c7e8149
font_01_sfnt_off0000f1d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D5 17508 bytes
SHA-256: 0a26918a6242dc9c511a72db68a6f425e24eeaeaf114a8d7f0f1176baded5e1b
font_02_sfnt_off00011f73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F73 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1