Malicious PDF — malware analysis report

Static analysis result for SHA-256 18839c459e3f3304…

MALICIOUS

PDF

84.6 KB Created: 2021-10-07 07:20:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 526feca102f84298cddbbb7e045ddd92 SHA-1: 1a0ec2ccda9e55654038ed4d3b7a8cd047b2b595 SHA-256: 18839c459e3f33048c1c6486fd8ffb251a31ad0e8cd600ce02c04b2e181a7ca4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple embedded URLs, with one specifically advertising a 'free download' for a popular game, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were directly extracted, the PDF structure and embedded links are indicative of a malicious document designed to trick users into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://smidgel.ru/uplcv?utm_term=free+download+clash+of+clans+apk+for+pc PDF link annotation
    • https://atvatextile.com/upload/ckfinder/files/xusafazelosopatipelov.pdfIn PDF document text
    • http://korealabels.com/ckfinder/userfiles/files/xodilovijolawemolavixo.pdfIn PDF document text
    • https://szpital-sulecin.pl/images/fckfiles/file/16780023933.pdfIn PDF document text
    • http://isspskola.lv/userfiles/files/38044354620.pdfIn PDF document text
    • https://postelezmasivu-praha.cz/ckfinder/userfiles/files/kipebuzuturimo.pdfIn PDF document text
    • https://tigaintan.com/contents/files/jemigis.pdfIn PDF document text
    • https://kamarkosong.com/contents/files/22061111937.pdfIn PDF document text
    • https://aalatour.com/basefile/b2caalatourcom/files/68665264687.pdfIn PDF document text
    • http://autosklo.sk/pictures/file/28319547673.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614bd68c1939e---15123544574.pdfIn PDF document text
    • http://fratellilongoni.com/userfiles/files/79222707454.pdfIn PDF document text
    • http://stepasidemedical.com/images/uploads/file/22935341931.pdfIn PDF document text
    • http://clinicaveterinariacene.com/userfiles/files/76985726196.pdfIn PDF document text
    • https://eagleegg5k.com/ckfinder/triplebuserfiles/file/mazoniputolejiruke.pdfIn PDF document text
    • http://drcleancenter.com/uploads/files/202109011818066285.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/jivufavowobowi.pdfIn PDF document text
    • https://manenshop.com/upload/files/84323381438.pdfIn PDF document text
    • https://nsstore.mx/ckeditor/ckfinder/archivossubidos/files/89322823058.pdfIn PDF document text
    • http://kleinschadenexperte.com/userfiles/file/kixesuvafopujeko.pdfIn PDF document text
    • http://retrolondontees.com/userfiles/file/6517677961.pdfIn PDF document text
    • http://mindatpeace.us/uploads/files/31011183474.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161585d8fcbaca---davinifetan.pdfIn PDF document text
    • http://galluccifaibano.com/userfiles/file/bibexodemiviterivege.pdfIn PDF document text
    • http://karat-dobremiasto.pl/userfiles/file/mizugixexawepeniratasujom.pdfIn PDF document text
    • https://techielingo.com/fck_uploads/files/986942293.pdfIn PDF document text
    • https://billard-hauri.ch/userfiles/file/18633847429.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_off0000e42b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE42B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC42 10680 bytes
SHA-256: 4ebee64b41003834ad8ecd69fe300d0a7034f67e83caac55cffef5bcb6fb338a
font_02_sfnt_off000114b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114B8 18700 bytes
SHA-256: 23ac33200aa182de0f72f9b1e2ac89f392b7a3a7ed89d7d4fe15997cd304cc2d