Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b831aab19334f94…

MALICIOUS

PDF

73.8 KB Created: 2021-09-08 19:32:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f3582895d9553a3cf9a8bc5e9263a19d SHA-1: 8241d77a2a54543cf7d88a8c8d85bf917e243fd7 SHA-256: 4b831aab19334f94cdac0aba12e8f7afc737a9663edd05a9d4e01cee8b152041
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, characteristic of a link farm designed to redirect users. The document body is unreadable, but the heuristics strongly indicate a phishing or redirection attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://archielectronics.com/userfiles/files/jizotazurivi.pdf In PDF document text
    • http://pyhunlian.com/uploadfile/file/jetogoxusaperituloru.pdfIn PDF document text
    • https://fluffy-chins.com/images/file/11565254327.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ecd169a80b---jesokifoduviwojuwegif.pdfIn PDF document text
    • https://maryamghiasi.com/images/upload/files/piruzowaremodiweje.pdfIn PDF document text
    • http://holidayservicemarsala.it/userfiles/files/95543990985.pdfIn PDF document text
    • https://fotofidelity.cz/userfiles/file/8662871229.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/72216112423.pdfIn PDF document text
    • http://domuran.pl/files/file/1341314342.pdfIn PDF document text
    • http://smcertificationservices.com/userfiles/files/69494878848.pdfIn PDF document text
    • https://yesilkoyluleriz.biz/resimler/files/36589418858.pdfIn PDF document text
    • http://knx-shop.ru/admin/ckfinder/userfiles/files/tujunomofikaralilojajol.pdfIn PDF document text
    • http://xaydunglenguyen.vn/upload/files/2ba62d.pdfIn PDF document text
    • http://tnhmc.com/userfiles/file/wojedoserire.pdfIn PDF document text
    • http://ksiclubcom.ksiclub.org/svnprojects/DHD/Source/images/files/91046967726.pdfIn PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/40789664564.pdfIn PDF document text
    • https://www.pollackmihalyiskola.hu/ckfinder/userfiles/files/dezisugodikazinumesesu.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/4944f4df9b9a4b7cc8188acf244d4b5e/texovogalibomexo.pdfIn PDF document text
    • https://hr-serdahel.hu/images/file/mubuvapotiv.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161348cf7a8269---zajisoba.pdfIn PDF document text
    • https://romalasergroup.com/userfiles/files/tonuzawapewifabuvazedo.pdfIn PDF document text
    • http://resetimpianti.it/reset/public/file/43623249910.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=four+vedas+in+malayalam+pdfPDF 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_off0000beaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEAA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d6c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6C1 10820 bytes
SHA-256: f280a021a50633c6bfa4e5b7c9b29e45b0ec70c0baee3dfa6d4aaa1a7acb0fd0
font_02_sfnt_off0000efa8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA8 16256 bytes
SHA-256: 3d295b656d485d0a7e74bfdd282c47d4319ac32dd663eab267cb66637240ff37