Malicious PDF — malware analysis report

Static analysis result for SHA-256 856cf14814c790cc…

MALICIOUS

PDF

71.5 KB Created: 2021-09-28 17:28:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 2c9f4ea8d0628b27cfb54f7e863b6a5d SHA-1: 2503b17ee7e849e9de5beaf5407dd66247c40ec3 SHA-256: 856cf14814c790cc270f010c2d3f3a67deb2bb222370deed1d5cfe9e73d4d4b9
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or appear to be disposable hosting, indicative of a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, and the document body was unreadable, so the rationale is based on the URL heuristics and AV detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://fxlcd.com/upload/file/74680263375.pdf In PDF document text
    • http://nesthomes.in/userfiles/file/luwuborelinanuzanidukun.pdfIn PDF document text
    • https://nothingbutsafetyglasses.com/userfiles/file/99678491259.pdfIn PDF document text
    • https://youkuvpn.com/upload/files/99003438407.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/26549523307.pdfIn PDF document text
    • https://ripedesign.com/app/webroot/files/fckeditor/file/45751379327.pdfIn PDF document text
    • https://scalping.ir/data/files/file/lofamawelunetefak.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f968b11ebd---rowus.pdfIn PDF document text
    • http://sportservistocik.cz/UserFiles/File/zotipofokidefibimedop.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/161527660ad2f8---rekok.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/16152e0a50bee3---tazufuviw.pdfIn PDF document text
    • http://vietsinphar.com/uploads/files/noruvomikotigizibujet.pdfIn PDF document text
    • https://gabconstruction.com/ckfinder/userfiles/files/62378861573.pdfIn PDF document text
    • https://cingenito.ca/upload/editor/file/pexinogixexotipipuziganud.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/5314un98lg3nmacmmro9faf3g8/lapugiwuperidisovasex.pdfIn PDF document text
    • http://huichem.com/ckfinder/userfiles/files/12826301591.pdfIn PDF document text
    • http://f-kcc.jp/user_data/userfiles/files/mikojalulanagap.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161403cc4b0802---85875363396.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/47e7ee4a5abb46a2d372383c8229c88f/wasimola.pdfIn PDF document text
    • https://xn--psg-9lac.hu/files/files/kaxusavesebukixob.pdfIn PDF document text
    • http://ros-grad.ru/fck_editor_files/files/66968413851.pdfIn PDF document text
    • https://samowar.ch/upload/file/tedokeralojikojinolu.pdfIn PDF document text
    • https://lifo-sea.com/ckfinder/userfiles/files/pagenekiwi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=troy+full+movie+with+english+subtitlesPDF 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_off0000b2bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2BC 17360 bytes
SHA-256: 772d529c3e263271350d0f9cba7012420838b1659ebbdedf11da8fff59bbc95f
font_01_sfnt_off0000df44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF44 10968 bytes
SHA-256: 819d63ad6ca3acfd4431852ed308ccaa2cc71f09b006d038fc54e2ecc1b16684
font_02_sfnt_off0000f89d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF89D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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