Malicious PDF — malware analysis report

Static analysis result for SHA-256 9387e8392ad84a87…

MALICIOUS

PDF

86.0 KB Created: 2021-09-03 16:47:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e74f30f16a92ed74ad4896c646db77bd SHA-1: 75c6f3d7bcfbb900bde1838648b9bb615c1cf4e3 SHA-256: 9387e8392ad84a87bbd780d41c1543176a7f346b88346823d74240143172639a
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous embedded URLs pointing to potentially compromised WordPress upload directories and other disposable hosting. These links likely serve to redirect users to malicious payloads or phishing sites, a common tactic for initial access via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c8a0ae4bd0d---58057936196.pdf In PDF document text
    • http://tranhdaquydep.vn/upload/files/vakosanamojovuwu.pdfIn PDF document text
    • https://finatwork.com/userfiles/file/fupiken.pdfIn PDF document text
    • https://daulte.ch/ckfinder/userfiles/files/88903617988.pdfIn PDF document text
    • http://sushiloverca.com/uploads/files/23035040231.pdfIn PDF document text
    • http://asiadomainstore.com/userfiles/file/9545766116.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aafdcb4e7b4---welaxiwurewosinejikejowa.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/be14c11fa54326acc5fbce052bfd7eee/12527969271.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077268b3f031---77229044612.pdfIn PDF document text
    • https://www.nuyew.academy/wp-content/plugins/super-forms/uploads/php/files/a722a04d63bd1d77fbcc2c2b756dacc0/23335494625.pdfIn PDF document text
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/xajudifo.pdfIn PDF document text
    • http://synphabase.ch/upload/file/29764055193.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/fuean1cuojkf6nal5kfrnq12k4/perevubuvakurisem.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/bd8jsinjfa2e2se0r84r689gfo/velolajul.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/32340947510.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c259c7b828a---17729190608.pdfIn PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e880f7a9684---fixasagenin.pdfIn PDF document text
    • http://studiotecnicobonoli.com/userfiles/files/ragesenudozemeveka.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1608109067e925---86899839781.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d5d8f227359---3029280174.pdfIn PDF document text
    • http://skyline64reunion.com/clients/e/ec/ec378541aa9b73e2b99de5ca5545ec21/File/6794194737.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b58c98a906d---sadosidewopixak.pdfIn PDF document text
    • https://sinarwaja.com/account/files/39453244381.pdfIn PDF document text
    • http://kepco-group.com/uploaded_files/userfiles/files/gabemogim.pdfIn PDF document text
    • http://eventclub.pl/userfiles/file/tasegozexolosanuke.pdfIn PDF document text
    • http://rspon.pl/images/wyswig_images/file/jusokuvifewiwobena.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=read+pdf+text+in+pythonPDF 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_off0000e77b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE77B 10540 bytes
SHA-256: 17e73ca95852227963daf7f6b6053833921baa858e4c58105e5ee349f68e3ba4
font_01_sfnt_off0000ff71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF71 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011783.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11783 19040 bytes
SHA-256: 5217592619f357d8364560ed86778877659d78e1744e201b0f7c0b27452a0bfe