Malicious PDF — malware analysis report

Static analysis result for SHA-256 857c8b58f20b83bf…

MALICIOUS

PDF

79.3 KB Created: 2021-09-30 15:13:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 465eda72b4aacc9e1c3137b244f4eb00 SHA-1: 8f920f687b99663a59784aa68ce2b104be07f1af SHA-256: 857c8b58f20b83bf9308b3003bd2536f0c42438a5bd0ea53c2efed58436c5a48
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically identified as a phishing trojan. It contains numerous embedded URLs that function as a link farm, directing users to potentially compromised websites. The presence of multiple external URIs and link farm heuristics indicates an attempt to lure users to external resources, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • 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 https://inwebjor.ru/uplcv?utm_term=infinite+health+gta+san+andreas+ps2 PDF link annotation
    • http://getdol.com/page_data/file/73040327888.pdfIn PDF document text
    • http://thenikharvconsultancy.com/userfiles/file/35726459259.pdfIn PDF document text
    • https://kibledergisi.net/resimler/files/2496569209.pdfIn PDF document text
    • http://diegogenna.it/userfiles/files/37064706429.pdfIn PDF document text
    • https://hoalavender.net/upload/files/furumizabiwakusogilabufex.pdfIn PDF document text
    • https://citytrafik.nu/images/file/42335689871.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614fb24c85448---51530358273.pdfIn PDF document text
    • http://wsmr.us/userfiles/file/83778267464.pdfIn PDF document text
    • https://dollarplus98.com/images/upload/files/82083214282.pdfIn PDF document text
    • http://chiesamadremarsala.eu/userfiles/files/momaliwutesibedeburod.pdfIn PDF document text
    • http://adfaveo.com/image/files/20210919_175225.pdfIn PDF document text
    • http://okwmd.com/upload/fckeditor/file/86375501622.pdfIn PDF document text
    • http://jcon-aps.dk/userfiles/file/fitadubakawugidanagov.pdfIn PDF document text
    • http://greenmodels.ru/uploads/files/85662473838.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153d97b19b4a---waxelejivebapulawo.pdfIn PDF document text
    • http://mq-water.net/upload/33108327825.pdfIn PDF document text
    • http://bctlorraine.org/userfiles/file/veligoxavunidowusip.pdfIn PDF document text
    • http://artanuji.ge/admin/ckeditor/ckfinder/userfiles/files/48653333029.pdfIn PDF document text
    • http://yossy.biz/userfiles/file/xiwowuwufuxudokefo.pdfIn PDF document text
    • http://utcsp.rustyramone.com/uploads/files/2088344129.pdfIn PDF document text
    • https://omnistopbollards.com/application/third_party/ckfinder/userfiles/files/bajinolixilixebuxe.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/a26ec3d267efee52f4e420f0913bad23/dilatoxopito.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/527e4fa3eff8be6a4eb6e50800ee4d5a/xepiwirol.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://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_off0000caeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAEB 10728 bytes
SHA-256: 4842abdabffaa6a62ed2c951ea6537e46e10eab5379f6beb65b86f4490efab65
font_01_sfnt_off0000e348.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE348 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB5A 21176 bytes
SHA-256: 4c4422785b2efb953779c94852f62e252bb015335f6fc3efaa6bcf7fbc97e253