Malicious PDF — malware analysis report

Static analysis result for SHA-256 9770cf8661958614…

MALICIOUS

PDF

70.3 KB Created: 2021-09-24 14:45:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 507736df0ec71f5a2983cc3d6cb431b2 SHA-1: 89c8a788bbe5d1cff8b9112fb541e79ac5aa6fba SHA-256: 9770cf8661958614d9adc53c21a3ce6dd35c2ef384717114333bc3025cbf678f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for Pdf.Phishing.Trojan and an ML classifier indicating maliciousness. The presence of numerous embedded URLs, many pointing to disposable domains and configured with UTM parameters, strongly suggests a phishing or link-farming attack. The document body, though heavily obfuscated, contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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://oniceh.ru/uplcv?utm_term=how+do+i+send+a+link+in+a+text+message+android PDF link annotation
    • https://greenlakecruises.com/ckfinder/userfiles/files/96486769612.pdfIn PDF document text
    • https://tauthuy.vn/upload/files/58229447444.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138195c7e499---jumakudoroboxipixowevob.pdfIn PDF document text
    • http://oxigensupplies.com/shipinc/userfiles/files/34440629841.pdfIn PDF document text
    • http://farashimirooz.com/files/tabopuz.pdfIn PDF document text
    • https://apartmani-mestrovic-krk.hr/files/fazusavidor.pdfIn PDF document text
    • http://wingmanresearch.com/userfiles/files/62012268187.pdfIn PDF document text
    • http://ambcavallon.eu/userfiles/files/lenikedobeg.pdfIn PDF document text
    • https://m-isc.com/userfiles/file/45473405453.pdfIn PDF document text
    • http://www.biogreeno.com/cms/ckfinder/userfiles/files/nugekigavubagerolot.pdfIn PDF document text
    • http://www.coverseg.com/uploads/ckfinder/files/vakiwufufunig.pdfIn PDF document text
    • https://daaeportrett.no/upload/file/wetutokirivajex.pdfIn PDF document text
    • https://alarrabnews.com/images/content/content/file/39829872966.pdfIn PDF document text
    • http://puzynowska-kancelaria.com/userfiles/file/60249834985.pdfIn PDF document text
    • https://cosanuesa.com/componentes/editor/ckfinder/userfiles/files/zixize.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/36103382965.pdfIn PDF document text
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/tolitodatuseruluxakoj.pdfIn PDF document text
    • https://stabiactiv.com/userfiles/file/gozinajutemuxunije.pdfIn PDF document text
    • http://sake-tori.com/images/library/File/wemozefonotifasasilo.pdfIn PDF document text
    • https://clubsecurite.fr/webroot/upload/files/zupodomirijaliwid.pdfIn PDF document text
    • http://ekvatorbl.com/userfiles/file/fasefadoxujisinip.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/d0af38cbd41b496dcad3d3354c97cf68/fatoxumiwikexesiximimovu.pdfIn PDF document text
    • http://www.kevimotor-rock.hu/files/files/dugawujazameraropikalipi.pdfIn PDF document text
    • http://talentfuturesservices.com/sharpinstitute/images/files/vituvufo.pdfIn PDF document text
    • https://cs-nippon-cp.com/mailmagazine/upload/files/16790244246.pdfIn PDF document text
    • http://art-ball.net/files/file/favogasaxepe.pdfIn PDF document text
    • http://cartopack.com/Images/file/vanojifufovug.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_off0000b4a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4A1 10864 bytes
SHA-256: dc6b70bd43ab2949894a555a9125eea1f1f784ad65f06fd3dc098c5f9b119630
font_01_sfnt_off0000cd86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD86 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e598.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE598 14792 bytes
SHA-256: 7412a3a7c45c11ea3aed5fb324c784c87bae27cee5bf78ea8128b374ae2a7fd1