Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c295b393e9cdcf2…

MALICIOUS

PDF

135.1 KB Created: 2021-08-08 14:07:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: db3221452c5416f88a684f1baf27e520 SHA-1: c1e0c2d80be0f08c82e36f3fb19e50f76bf278b5 SHA-256: 5c295b393e9cdcf221132b8081684d060b33062041819b68b3e8cb71e2e136c9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The file contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm to distribute phishing lures or malware. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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=que+es+ser+cr%C3%ADtico+pdf PDF link annotation
    • https://fototipia.hu/files/files/83927046974.pdfIn PDF document text
    • http://asupuro.com/upload/save_image/files/18965159246.pdfIn PDF document text
    • http://stevis.cz/files/file/81777865370.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/055de5b7a7c2810879c96ac6e413988b/46307839564.pdfIn PDF document text
    • https://aterhesseg.com/up_image/file/79110544678.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/acfe032606b428d122bc2abfe0a0d0fd/govusonov.pdfIn PDF document text
    • http://studiogalata.it/userfiles/files/86214146315.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/viduxanigavifa.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/6kjcpsqc719ntes271dpe6mdlb/18837251712.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/dopatemafafowigavudu.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210719070140.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/b5674314db22bb5c5331e79f28dbc190/fupevugaxuxu.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c8a3827c993---vufijataruma.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/zijugikex.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/i1928ev4dvajelmi7g8s8boob4/rupevodusivuf.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/sefipametiruturidokakuwif.pdfIn PDF document text
    • https://ce-mi.pl/uploads/userfiles/files/98113884917.pdfIn PDF document text
    • https://hostingpazari.com/calisma2/files/uploads/76806922162.pdfIn PDF document text
    • http://royalwedding.jp/images/blog//file/resesukuzobetafu.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1607ebb8e4b891---lamuputepumukisiwuk.pdfIn PDF document text
    • https://billionbosses.com/ckfinder/userfiles/files/rujumenaliwapumefu.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/5dthuis0v4uupug3b93t9m3udj/rogopuvuzenuma.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/12222528013.pdfIn PDF document text
    • https://okazdedziecko.pl/_files/Media/file/bibulo.pdfIn PDF document text
    • https://aihr-iadh.org/uploads/FCK_files/file/3026587924.pdfIn 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://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_off0001a993.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A993 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001c1a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C1A5 19376 bytes
SHA-256: b05b66f46ef3a0de0ad826c61070e7c1215c2a0ff0b1c3559acd18b5c0cfe79c
font_02_sfnt_off0001f3e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F3E8 10520 bytes
SHA-256: 7f17ff889581789c0ebb91d8f7a1f66995666fbcbe0151d3c2b8105a69822eca