Malicious PDF — malware analysis report

Static analysis result for SHA-256 96e9c8c88dba0e34…

MALICIOUS

PDF

91.5 KB Created: 2021-09-18 12:21:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c5b71578280f58d873fb2f1f0f8d16dc SHA-1: acdc48582a143ae83cc4d404bdbd902faa7f0b57 SHA-256: 96e9c8c88dba0e34f49f6280f0593c7e249747c7af5cd072fb75dfabe4eb396a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous external links and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest the primary purpose is to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://tuivaivietnam.com/uploads/files/rematezegose.pdf In PDF document text
    • http://veoguidecostarica.com/ci/userfiles/files/marugujixidim.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161320d9092271---94980399968.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/e629e1dd0e788f14bc94fc9e6bc50335/zofutalixenuzi.pdfIn PDF document text
    • http://e-sheremet.com/img/xokigovowopelaf.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/rphdsebp745s83nq2achir920e/xulidinulixenixumepudur.pdfIn PDF document text
    • https://specializedfacilitymgt.com/public_html/userfiles/file/92186643700.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/7a63f128c746d28efcd0301a02219af3/mujinodulidavakerutarul.pdfIn PDF document text
    • http://skncn.com/u/files/48045243486.pdfIn PDF document text
    • https://asiastudy.in/ckfinder/userfiles/files/fokuzorazanopu.pdfIn PDF document text
    • http://goldenpeak.it/userfiles/files/zogakepivewizoxiz.pdfIn PDF document text
    • https://hanomanberjaya.com/contents/files/donewikusumale.pdfIn PDF document text
    • https://lapakunited.com/contents/files/61529456454.pdfIn PDF document text
    • https://landbondcorten.com/attachment/file/5165dd0c0b23ae61777c234689aad6d3.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/29832994933.pdfIn PDF document text
    • https://www.gryf-wet.pl/ckfinder/userfiles/files/35890276075.pdfIn PDF document text
    • http://klaaswester.nl/img/file/kimemivabonineguvutamuru.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16135cd7711720---xejavulilokafo.pdfIn PDF document text
    • http://sakuragiramenandsushi.com/uploads/files/13796249548.pdfIn PDF document text
    • http://savoie-outils-coupants.com/ckfinder/userfiles/files/9190440488.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/nobobufadidamupibobami.pdfIn PDF document text
    • http://bargiel.com.pl/ckfinder/userfiles/files/30601883135.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=flute+notes+and+finger+positionsPDF 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_off0000f746.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF746 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010f58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F58 21652 bytes
SHA-256: 110299936469d246c11680c1bb713002d8f95b8a40b3065645b6eb81ebfc7b74
font_02_sfnt_off00014818.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14818 10748 bytes
SHA-256: 5316b44dc5b21e400cf4b10402d4a86139802992cfcb40d10c05caf230a67429