Malicious PDF — malware analysis report

Static analysis result for SHA-256 81197d893d9b4866…

MALICIOUS

PDF

67.4 KB Created: 2021-09-30 14:24:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 805a8fb87073d4329d3414bf11999e90 SHA-1: 928c842088b977baf3a817e27132a29f9aeb7726 SHA-256: 81197d893d9b4866afc89ecea3acb15547c474082f731d012628b0e654c9a741
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious. It contains numerous links, many pointing to compromised CMS upload storage and disposable hosting, suggesting a link farm designed to redirect users. The presence of external URIs and the overall structure indicate an attempt to lead users to malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://adsbudget.net/userfiles/file/serabagokixatetudetazet.pdf In PDF document text
    • https://sevenhillsgroup.net/ckfinder/userfiles/files/61310816198.pdfIn PDF document text
    • http://dungcumaymoc.com/Images_upload/files/zidopizax.pdfIn PDF document text
    • http://pusheng168.com/uploadfiles/20210901085211.pdfIn PDF document text
    • http://rubivina.com/Images_upload/files/xefegofapovuzigas.pdfIn PDF document text
    • http://www.onlinenieuwsbriefversturen.nl/gebruikers/afbeeldingen/90360524719.pdfIn PDF document text
    • http://thietbiotovn.com/Images_upload/files/31897407616.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/161381618a561c---89958419285.pdfIn PDF document text
    • https://butchercurnow.com/img/shop/contents/xofumelasu.pdfIn PDF document text
    • https://1000families.eu/userfiles/file/65301400239.pdfIn PDF document text
    • http://popmetre.com/news/files/falorixorexepogedilufed.pdfIn PDF document text
    • https://puntodeplacer.com/userfiles/file/25368643989.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/273b15356c61ba05e09911b9e25b1a7d/16671048871.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16134e6987a458---11768740234.pdfIn PDF document text
    • http://www.waetsukai.jp/system/ckfinder/userfiles/files/26760751146.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145268d79f17---tikerog.pdfIn PDF document text
    • https://kapefashion.com/files/files/38811634604.pdfIn PDF document text
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/rajadegivepu.pdfIn PDF document text
    • http://miet-boot.ch/images/uploadedimages/file/60207611714.pdfIn PDF document text
    • https://desense.eu/uploads/wysiwyg/files/25759524604.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/11ac4f04bdad6dc41ac17505ba6288ed/23494963881.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=light+platinum+gba+romPDF 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_off0000ac2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c43c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC43C 14504 bytes
SHA-256: 88ec3715e7d29b151decb2108fc98544a0b433d9226310ae2a8088468f74ab5b
font_02_sfnt_off0000e8c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8C2 10596 bytes
SHA-256: 9410cd01f72d482421d5e6f68792fa91f4d7bf0b91c75712450be2ff2c2b4551