Malicious PDF — malware analysis report

Static analysis result for SHA-256 c967259a14c09dbb…

MALICIOUS

PDF

65.8 KB Created: 2021-06-19 16:54:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: fb64f798ea919e60cff42acafbf2af1b SHA-1: 9364034fe410f13d617e93269e8d2d885445fc22 SHA-256: c967259a14c09dbb4cf71848681dca5e57846a9d2b8f1480e441600489613615
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs that point to compromised CMS uploads and disposable hosting, suggesting it functions as a link farm to distribute further malicious content or conduct phishing. The document body, though heavily obfuscated, contains references to 'piano pdf' and 'wkhtmltopdf', which are likely decoys.

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://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/8b0e6afc41405351403acde8e6df3948/wulafabowotaxanez.pdf In PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/50cfc1e6bd4e4062724a777e417866e7/79180318359.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8746f3ded4---20655015165.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/80fe208b68b83fcee34425d1d248da26/pijoler.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/dff3e0cabc46407f3d09309aa1ad316b/67401646968.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0f5dadee81---73175881298.pdfIn PDF document text
    • http://mega.kz/media/upload/files/78007217735.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/6a1118c359bd52ad0486251c7e3102a8/63895738622.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16094dfb1e0c43---11168990183.pdfIn PDF document text
    • http://altinay-law.com/images/file/56828736641.pdfIn PDF document text
    • http://wallsfamilyreunion.com/clients/876683/File/xewafikuxakewudadumami.pdfIn PDF document text
    • http://filtrydokoparek.pl/img/all/nulatumarizixefotosejijas.pdfIn PDF document text
    • http://okmarin.ru/userfiles/file/zulixex.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cdf4e735ce4---kuxemomo.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/160703816c57d1---bovavejaromexafisasote.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=once+upon+december+piano+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c2ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2AC 5260 bytes
SHA-256: e6aa217f262ab8c9980b920996254fbec587c02cbd6d87ac1b6df0a27acd3c8f
font_01_sfnt_off0000d46f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD46F 11260 bytes
SHA-256: 8c0473923263f1e553e2c33a8757d97a806eeb380135055294a4aefe4d709d3c