Malicious PDF — malware analysis report

Static analysis result for SHA-256 c624b64878a3439b…

MALICIOUS

PDF

84.6 KB Created: 2021-08-30 14:34:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: ebf22da133cd7b9347f590225e70812f SHA-1: fbc449fb116147c381c0694c0997aa3d479be061 SHA-256: c624b64878a3439b1a5bfdd93a964e728522cd7795f96f9fe1618ba533f602ba
156 Risk Score

Malware Insights

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

The PDF file contains a link farm that redirects to multiple external URLs, many hosted on compromised CMS uploads or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The primary attack pattern involves luring users to click on these links, which could lead to further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 https://kme.pl/global/app/webroot/uploads/file/16253206352689.pdf In PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2f374ec000---49109074236.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-8-4/20210804044930199808.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/23ce2af3e5c180b30e1525c34a1ff603/dikitetupaxisujozajutet.pdfIn PDF document text
    • https://ak-oroslavje.hr/files/59306204983.pdfIn PDF document text
    • http://cementfeet.com/userfiles/file/muvevejonewuvovapusojoxur.pdfIn PDF document text
    • https://airflow-skateboards.com/upload/file/mutan.pdfIn PDF document text
    • https://aspirans.com/files/file/22350955174.pdfIn PDF document text
    • http://mis.nrru.ac.th/gradjournal/ckfinder/userfiles/files/91334988984.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/160943a0572b96---xokaratomo.pdfIn PDF document text
    • https://aradovan.com/userfiles/file/92605205976.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a4b65dcac41---vogigisiwawifowiruga.pdfIn PDF document text
    • http://ros-grad.ru/fck_editor_files/files/53937575421.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161167a2902d0b---60507993092.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd42e7ee56---58872957561.pdfIn PDF document text
    • http://asfcursillo.com/clients/879797/File/balozosivazevobarofaz.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/vawowekeropugib.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/vifvgdl1v3mocpcmsatuhi0ta4/43349844487.pdfIn PDF document text
    • http://schnauzermountainminiatures.com/clients/17729/File/dakulutonujinofux.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160790b45c3c30---83708202440.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=bootstrap+app+themePDF 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_off0000e740.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE740 17248 bytes
SHA-256: bcd0251c2ba481cf952af538ce3194f25d5aa82b285bcd8f19ae537dcbfa1b74
font_01_sfnt_off000113ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012c01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C01 10328 bytes
SHA-256: 1db3f158ebe53055efe66a98fd9f8c1a4c73e5c551574ff9f5ea64ba956acc74