Malicious PDF — malware analysis report

Static analysis result for SHA-256 35a89b6f9d2e1def…

MALICIOUS

PDF

84.5 KB Created: 2021-09-18 12:27:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4780aec1a2d6cfed6799bce0008e67ee SHA-1: 15e88835823f1f7d79ebf7cad087c93b4f9bc148 SHA-256: 35a89b6f9d2e1def5ee91a8679af3558cc3e1d7130a1004f8762c982dfb58c52
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. Multiple heuristics indicate that the PDF contains numerous external URIs and links pointing to compromised WordPress upload storage and disposable hosting. The primary purpose appears to be directing users to potentially malicious external sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://krisoc.ru/uplcv?utm_term=new+game+mobile PDF link annotation
    • http://ozanatalan.com/iboard/includes/userfiles/files/56646862914.pdfIn PDF document text
    • http://lagunaapartman.hu/images/user/file/74923555261.pdfIn PDF document text
    • http://chanhbon.vn/media/ftp/file/gawikinomerosozimugar.pdfIn PDF document text
    • http://mikol-styl.cz/userfiles/file/jobesagubafeludizuzuvimab.pdfIn PDF document text
    • http://nasfthr.com/userfiles/file/livufimisiregekumiva.pdfIn PDF document text
    • http://www.village-gaulois.org/gestion/ckfinder/userfiles/files/66081531196.pdfIn PDF document text
    • http://osmed.cz/app/webroot/files/files/23260554059.pdfIn PDF document text
    • https://www.drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161304369ead8b---labaxulafagidezizimeno.pdfIn PDF document text
    • https://podereilmontaleo.it/writable/public/userfiles/file/81997651600.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134d6056853d---zozisofuzedewosagimi.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161403d9409d78---mowavesa.pdfIn PDF document text
    • https://braindevelopmentmaps-org.neurondevelopment.org/userfiles/files/86143563949.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/giferemivetamugavezomaw.pdfIn PDF document text
    • http://cdseoulps.com/uploadfile/fckeditor/file/rukagoxuposivoretug.pdfIn PDF document text
    • https://fluffy-chins.com/images/file/xalesozusuvodakulidek.pdfIn PDF document text
    • https://thefertilizergranulators.com/d/files/69644010334.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/raloxulufa.pdfIn PDF document text
    • https://matraci.info/UserFiles/File/4766054495.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/78131965895.pdfIn PDF document text
    • https://dongphuchuytai.com/upload/files/rigabotoge.pdfIn PDF document text
    • https://orcasproje.com/userfiles/file/zuzomegetumop.pdfIn PDF document text
    • http://lesbambousbleus.fr/ckeditor/upload/files/2884353385.pdfIn PDF document text
    • http://caerulumpharma.com/upload/files/ladinubezogofejuliropedis.pdfIn PDF document text
    • https://kp-bs.ru/upload/files/9632829345.pdfIn PDF document text
    • https://ascii.tn/web/cgi/file/5111941686.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_off0000e7ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7ED 10184 bytes
SHA-256: 091845773723c2f883f0d6df25b59d7b147b1e73fa027ec974f9f2135b92ab0f
font_01_sfnt_off0000fec1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEC1 17596 bytes
SHA-256: 7fa622c7bef62b4f5060e24b90f3e92709b6a0cd24283a348e6d02ad8fdcc0ff
font_02_sfnt_off00012c7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1