Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8811a675a41c1b9…

MALICIOUS

PDF

85.9 KB Created: 2021-09-19 01:01:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d67191207b59c16be6fadcfcd9f99685 SHA-1: 3da80a3ff56e92fd134cf2853aa3fb5f06fa66e1 SHA-256: d8811a675a41c1b94767bbe18d7343159d316e003a3ad1bca2c281e33e215924
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised WordPress upload directories, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, but the presence of multiple external URIs and compromised CMS links is sufficient evidence of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://nppgursaraijhansi.in/ckfinder/userfiles/files/4091634912.pdf In PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161431c993bdbb---kuxowetixit.pdfIn PDF document text
    • https://kakakmanis.com/contents/files/37742009128.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/5c1aea670016dbd48b5fa4d670b40b51/nilebu.pdfIn PDF document text
    • https://terracetemayonetim.com/upload/ckfinder/files/nusamotozuniduw.pdfIn PDF document text
    • http://yishiweb.com/upfiles/files/20210907_212236.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613588e17ec49---45860450868.pdfIn PDF document text
    • http://wangguanhardware.com/userfiles/file/78345646922.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16138490c62bec---37506865776.pdfIn PDF document text
    • http://thietbigas.net/media/files/risabimazijonejufuku.pdfIn PDF document text
    • https://inprovitecuador.com/ckfinder/userfiles/files/55861416324.pdfIn PDF document text
    • https://kidneystonetreatment.in/userfiles/files/luwixijofaweto.pdfIn PDF document text
    • http://dooroc.com/tk/upload/file/duvizepokejosodajoxu.pdfIn PDF document text
    • http://pampa.be/uploads/userfiles/files/gefufakalejapapuroxixil.pdfIn PDF document text
    • http://radyoislam.com/resimler/files/ruwuxade.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/23c0f4c0a0a9facb105a5aae53413432/42103154547.pdfIn PDF document text
    • http://ktcyy.com/ckfinder/userfiles/files/2646962356.pdfIn PDF document text
    • https://hiroyoung.com/data/files/97707197142.pdfIn PDF document text
    • https://inprovitmexico.com/ckfinder/userfiles/files/15810925749.pdfIn PDF document text
    • http://www.moyekolodin.com/files/22437806532.pdfIn PDF document text
    • https://stpeterscbs.ca/ckfinder/userfiles/files/kikebugifiruj.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/42587725054.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/161440b90d70d2---64098685030.pdfIn PDF document text
    • https://deltarealestate-eg.com/userfiles/file/putokomorixalolubugasiz.pdfIn PDF document text
    • https://fullgame.hu/uploads/files/firowakedotopajukevut.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=swashbuckler+pathfinder+2ePDF 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_off0000e7c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7C8 11208 bytes
SHA-256: dd838161b682ca2d6a295396936b6996f20bbdfe1f7148f61f170928955109e8
font_01_sfnt_off000101e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119F2 18296 bytes
SHA-256: 4d3931a5283d45f4d5502ed07ad8df26e470943a07ffa03382e84507184eb2f2