Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b66719112f8d0da…

MALICIOUS

PDF

83.8 KB Created: 2021-06-09 09:23:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 4f4a260d62b9295a5e33eef75c9aace6 SHA-1: 3de9561c36f754a6dd6ba910e8fdcba1509fb011 SHA-256: 8b66719112f8d0dad992f68038a15251f37f4a4701b58cbd572d8223eb1d86cb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous links to external websites, many of which are hosted on compromised WordPress sites. The document body, though heavily obfuscated, contains text related to 'Kmspico office 2016 free download', suggesting a phishing or malware distribution lure. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=kmspico+office+2016+free+download PDF link annotation
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16090539abd6ec---saxibekudejifo.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16071cc8e21f34---lubinirokobawet.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085a7e3dd388---81651257749.pdfIn PDF document text
    • https://mziagroup.com/wp-content/plugins/super-forms/uploads/php/files/pvo3o4c9hlieg0s2ehseo9qsn1/fipukotapulakeja.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a33a588b4c4---vetefakikuj.pdfIn PDF document text
    • http://hoshitorionline.com/uploads/files/vodewalig.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c073098cb9---28688095698.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160822c1db8522---27553177300.pdfIn PDF document text
    • http://www.haztartasigepszakuzlet.hu/pics/file/47933746140.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/08092fbbc29d65749c60c69414b7fa45/25315842728.pdfIn PDF document text
    • https://casabresciani.it/uploads/file/zaruguwanatunemef.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160872d7e41acd---11350956572.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/16094678a41b5a---zuxafoguxixiperekibe.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/27116424732.pdfIn PDF document text
    • https://artenika.pl/fck/file/kureku.pdfIn PDF document text
    • http://willbramephotography.com/38687350526.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095e7bd90036---64868445847.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f852.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF852 5844 bytes
SHA-256: c2c6b452cd5c5525ed5c6a9b7d784f7f651b9569e94391fbf0ed93f1ad0712a8
font_01_sfnt_off00010c42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C42 24604 bytes
SHA-256: 88563953996273ab5a6807ff9d8dac2bf93dd7a65895fb1e9023cf7d7e36ea06