Malicious PDF — malware analysis report

Static analysis result for SHA-256 81f9588b5d526725…

MALICIOUS

PDF

80.1 KB Created: 2021-10-19 02:49:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 4963a75d5e15f00947c07bfdfbd5e896 SHA-1: 63c33f7c1b98d4fe77b771d17f75bc5c18da3d74 SHA-256: 81f9588b5d526725d3ff96c1a85687cae3193ca6cab317e11c90555806b94388
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites or disposable domains. The primary goal appears to be luring users to potentially malicious or phishing content through these links.

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 http://xn--b1amishc2fb.xn--p1ai/ckfinder/userfiles/files/33216697306.pdf In PDF document text
    • http://inter-travel.hu/_user/file/9702052892.pdfIn PDF document text
    • http://nenayu.com/filespath/files/20210923111144.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/aktt12sr5ha6icf4oougsp0drq/risovozoki.pdfIn PDF document text
    • http://0vote.com/ckfinder/files/rakapijo.pdfIn PDF document text
    • http://gibkrakow.pl/uploads/files/58523809477.pdfIn PDF document text
    • https://www.hotel-restaurant-plainfaing.fr/ckfinder/userfiles/files/nizuxeladuwiwilodivevi.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/16153639e7b109---ximuvaj.pdfIn PDF document text
    • https://thehideawayresortpattaya.com/userfiles/files/tifonubeviwe.pdfIn PDF document text
    • http://gns3.swiz.eu/files/editor/nidom.pdfIn PDF document text
    • http://xn--80aafmoni2biho.xn--p1ai/admin/ckfinder/userfiles/files/pegafoko.pdfIn PDF document text
    • http://chiron-ventures.com/chiron/home/img/upload/files/210905142051625654gwktx.pdfIn PDF document text
    • https://gmt-tw.com/app/webroot/userfiles/files/29371846513.pdfIn PDF document text
    • https://dolaodong.com/userfiles/file/deliwutut.pdfIn PDF document text
    • https://artofsurfing.com/preview/ckfinder/userfiles/files/ledokizilabuluvulipoxa.pdfIn PDF document text
    • http://julianina.de/upload/file/21201632733.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/bp7pq9a0bgqdoicu3bjp0gr9dn/94312012781.pdfIn PDF document text
    • https://fiscconsulting.com/userfiles/file/ragevakinejeratezapi.pdfIn PDF document text
    • https://laznia-radom.pl/userfiles/file/31974131216.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16147cf44ed5b8---55241758395.pdfIn PDF document text
    • https://kawanmto.net/contents/files/47760082714.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/cmwvf4RlXg4/uplcv?utm_term=free+event+planning+spreadsheet+templatePDF 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_off0000d313.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD313 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB2A 10760 bytes
SHA-256: 25f07e3386a6d9e2b33f4985b8319cd46020b8ebf5e3f91ccf2619afce66656b
font_02_sfnt_off00010375.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10375 18708 bytes
SHA-256: ad5b059b087dfd956b71fb8536ee4216d95ddd7041fefd56d10f3873f254e38d