Malicious PDF — malware analysis report

Static analysis result for SHA-256 c977f6793335e713…

MALICIOUS

PDF

86.0 KB Created: 2021-09-19 03:26:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9cc0ad08255ebc33e8c78734314be599 SHA-1: 4c9744feaf8acc6efecf1b3138f5c69dda8c8e9f SHA-256: c977f6793335e713c7b7d62de37aa60953370c510dc6483391ce754ff37c3c99
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous other PDF files, many hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of external URI heuristics and the nature of the links suggest an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://bk.knu.ac.kr/ckfinder/userfiles/files/3260839491.pdf In PDF document text
    • http://tivatijapan.com/uploads/userfiles/file/74598006485.pdfIn PDF document text
    • https://bselink.com/userfiles/file/tofiruguzanekexa.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/52196270546.pdfIn PDF document text
    • http://rurisnet.org/images/file/65666897879.pdfIn PDF document text
    • http://www.temaricerca.com/entry2013/admin/ckfinder/userfiles/files/35479466915.pdfIn PDF document text
    • http://themadthinker.com/temp/vinney/HTML/userfiles/file/ferotaforazuw.pdfIn PDF document text
    • https://www.zolmedis.lt/ckfinder/userfiles/files/29720788566.pdfIn PDF document text
    • http://nayyaralidada.com/alpha/ckfinder/userfiles/files/xewazi.pdfIn PDF document text
    • https://slide-bearing.com/d/files/lapebatonivikiruwosifuxe.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/ee73cf703ad092206d9b2c2555c96f25/vovilovixoduladuj.pdfIn PDF document text
    • https://3drm.bg/uploads/pictures/files/binopokubufopokani.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613f253365a1a---fagowu.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/jexefinafetokegikuv.pdfIn PDF document text
    • http://pcserviszlin.cz/ckfinder/userfiles/files/lafowupukazujogijufimas.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/327b013ec7d1f98778dee23dc261693a/bowotijevos.pdfIn PDF document text
    • https://sikanderajam.com/Robinson/ckfinder/userfiles/files/vazaxin.pdfIn PDF document text
    • https://brtim.com/uploads/wysiwyg/files/89723806707.pdfIn PDF document text
    • http://huntland.hu/upload/file/widapogiso.pdfIn PDF document text
    • https://www.mds-horizons.com/upload/files/vunugapinatamiw.pdfIn PDF document text
    • https://reviewz.eu/app/webroot/files/userfiles/files/jifofiligebati.pdfIn PDF document text
    • http://all-premium.com/user_file/files/52245996697.pdfIn PDF document text
    • https://elitstroycraft.ru/source/file/lavelogurelelomivugifoxon.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=pokemon+flare+downloadPDF 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_off0000e99c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE99C 10336 bytes
SHA-256: 8400ae9ca8d58a45eb7263f56aabc405f413fc1889f19a7387dc235e695599c8
font_01_sfnt_off000100f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100F2 18832 bytes
SHA-256: e00ca8813efd15c7a4b1c31aac19d53b0383da163b0be95c12d2baa093afc97c
font_02_sfnt_off00013271.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13271 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1