Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f81cce3efcff16c…

MALICIOUS

PDF

78.6 KB Created: 2021-09-04 01:55:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: fdf73efbe4786eb8d096fb92069f75da SHA-1: bc2ff9b22ae497794f6045d1d4b8db3f1fdcdaf7 SHA-256: 4f81cce3efcff16c6805500c2c6ceb2fdc1e5059539dfdc690f4bb52e8d0d91f
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious. Heuristics indicate it functions as a link farm, with numerous URLs pointing to potentially compromised CMS upload storage and disposable hosting. The document body is heavily obfuscated, suggesting an attempt to conceal its malicious intent, which is likely to direct users to external sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://dimensionshoppe.com/alpha/ckfinder/userfiles/files/metelizozedevageko.pdf In PDF document text
    • http://artsar.pl/userfiles/file/rawet.pdfIn PDF document text
    • http://smenergy.kr/uploaded/file/1229747017612f16368d535.pdfIn PDF document text
    • http://diysmart.net/userfiles/file/29780338782.pdfIn PDF document text
    • https://chauphongasia.com/wp-content/plugins/super-forms/uploads/php/files/brh44lthikhj82cmhkcc2pk1os/nudutomikexelexov.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/xabirifaxobo.pdfIn PDF document text
    • https://travelstore.tn/userfiles/file/nunofigoxi.pdfIn PDF document text
    • https://led7.ru/file/wajimewiges.pdfIn PDF document text
    • https://atvatextile.com/upload/ckfinder/files/rusozikazatudej.pdfIn PDF document text
    • https://nedimgame.com/calisma2/files/uploads/gevelunizegidofosubu.pdfIn PDF document text
    • https://www.fishhabitatnetwork.com.au/application/third_party/ckfinder/userfiles/files/1110116396.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/d920568e142f83e23bbeaba9924ff891/kojuvuxavudetovo.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078f253795ab---77892955097.pdfIn PDF document text
    • https://www.prestigeautobody.com.au/wp-content/plugins/super-forms/uploads/php/files/813d811d29e17c08efd2ff5565ed209b/mufudodub.pdfIn PDF document text
    • http://babamoleskine.com/files/file/44126861575.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075221e8be1d---fedawe.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c5ef93b3b---20768162640.pdfIn PDF document text
    • http://www.iuoelocal870.com/kaizen/ckfinder/userfiles/files/didikuzapiv.pdfIn PDF document text
    • https://traveletrust.com/basefile/traveletrustcom/files/27137274026.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a2ed8774f07---xibozonokapaj.pdfIn PDF document text
    • http://baschin-heizung.com/meineBilderAlbertGrundschule/file/86020388125.pdfIn PDF document text
    • https://tlproduct.com/userfiles/file/96127027121.pdfIn PDF document text
    • http://rauvuonsach.com/images/uploads/files/82490786011.pdfIn PDF document text
    • http://af.ssla.ru/images/fornews/files/36583954460.pdfIn PDF document text
    • http://aahsclassof1978.com/clients/b/b6/b6117739535924054831d33ecd54b00a/File/wobapinetulevofuzet.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=demigod+diaries+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_off0000ce12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE12 10596 bytes
SHA-256: f2928baae9d727c1a418a51357d4f560e3cedf17c09359c8091d4eb85ac91964
font_01_sfnt_off0000e609.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE609 17832 bytes
SHA-256: a0b7de46a6161194c356b271c094c0f0785b9b902933c0206516a22583109aff
font_02_sfnt_off00011452.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11452 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1