Malicious PDF — malware analysis report

Static analysis result for SHA-256 c857191500114fc0…

MALICIOUS

PDF

81.6 KB Created: 2021-09-13 00:47:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: faf8ebc68327e6f44a36e65db058ddbe SHA-1: c325bbb1e73e56ad6f41544ff8a0e2e5bee23f27 SHA-256: c857191500114fc0c32309f566f8d3ec76341d67a294b2bd7316432b99cfebde
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous external URIs pointing to other PDF files hosted on various domains. The ML classifier also strongly suggests malicious intent. While no scripts were explicitly extracted, the PDF structure and extensive URI usage are indicative of a campaign to manipulate search engine results or distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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.
  • 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://open-call.fr/uploaded/files/34735170532.pdf In PDF document text
    • http://rollfactorytogo.com/uploads/files/kasunafukemirabewe.pdfIn PDF document text
    • http://bjqyms.com/filespath/files/20210902234615.pdfIn PDF document text
    • http://palmdale.thepokeluau.com/uploads/files/88519628789.pdfIn PDF document text
    • https://jpjplumbingandheating.com/FCKeditor/file/63292408292.pdfIn PDF document text
    • http://www.espaciocultivarte.com/ckfinder/userfiles/files/67016174823.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/38a5751384d6c2e608f8a163f96bc5ba/baxuvebamitimazazijele.pdfIn PDF document text
    • http://perila-vrn.ru/userfiles/file/dolizo.pdfIn PDF document text
    • http://cec-intl.ru/app/webroot/files/file/ximagavisipawom.pdfIn PDF document text
    • https://lemarko.com/userfiles/file/gipadujopibepemegerag.pdfIn PDF document text
    • http://huonglonghotel.com/uploads/image/files/xiviroromalagobediluwujez.pdfIn PDF document text
    • http://campfirewtx.org/userfiles/file/jomobapejeme.pdfIn PDF document text
    • http://bibliotekaludwin.pl/img/upload/files/wimiganijutajepokop.pdfIn PDF document text
    • https://pediatricpotentialsnj.com/PP/PPpng/files/tewawugilodifuwawori.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/161367e4c3a685---17460792428.pdfIn PDF document text
    • https://www.corpeverest.com/ckfinder/userfiles/files/sojozobokotidexikikudiz.pdfIn PDF document text
    • https://vinadesigndanang.vn/uploads/image/files/retow.pdfIn PDF document text
    • http://dlzj.net/upload/files/20210912103326690473.pdfIn PDF document text
    • https://cristalparkhotel.com.ve/ckfinder/userfiles/files/91890448708.pdfIn PDF document text
    • https://pernambucoimortal.com/imagens/files/67777333769.pdfIn PDF document text
    • http://tetrafluoro.com/upload/files/wijagoroxixatamudu.pdfIn PDF document text
    • https://cornerstonelaw.eu/userfiles/file/60892209784.pdfIn PDF document text
    • https://ermolino.mebel18.com/uploads/files/wudadibibulujusowilun.pdfIn PDF document text
    • http://pcccmiennam.com/media/ftp/file/xakinijapatedudijam.pdfIn PDF document text
    • https://thebookonpersonaltransformation.com/FCKeditor/file/rexigej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=hello+guest+apk+download+androidPDF 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_off0000d886.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD886 17524 bytes
SHA-256: efc6ae92311bfed86e3a92b83356f886e42001ad47c43f30dbab833c2fe33a8e
font_01_sfnt_off00010601.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10601 10836 bytes
SHA-256: 941d7fc1826e12dcc58127656d7214a4619c49b78f65cff6dab74a85b9dadb6e
font_02_sfnt_off00011efe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EFE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1