Malicious PDF — malware analysis report

Static analysis result for SHA-256 36da4ba7ce885f4e…

MALICIOUS

PDF

94.5 KB Created: 2021-08-02 12:46:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 56d57239d4f41bc4b24a8478127de29a SHA-1: 2a722db0cd2c5e7393fcacf1b0668974e594b63c SHA-256: 36da4ba7ce885f4e9be038086ba3ad9c1312aee8ab2c98792a57e98b9a2c6373
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external domains, many of which are hosted on compromised or disposable infrastructure, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this. While no scripts were explicitly extracted, the PDF structure itself likely facilitates redirection to these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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://rh4-h1tapi-turbo.com/contents//files/nerozekomuriwivipugojiwi.pdf In PDF document text
    • http://holzbau-napetschnig.at/60786414255.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/160815bdc1451a---gemimitekedebotikitutenor.pdfIn PDF document text
    • http://samilove-payitforward.com/clients/f/f9/f9b0b202ed5d2cb263a89f8a9bd08a94/File/wosubuxeniwovizenozuz.pdfIn PDF document text
    • http://cjatkinson.com/userimages/17238482227.pdfIn PDF document text
    • https://tempatpasang.com/contents//files/45443276767.pdfIn PDF document text
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074f87fc0ef8---raronu.pdfIn PDF document text
    • http://starke.ca/clients/84205/File/5996489772.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607258ffd0f5c---65388483203.pdfIn PDF document text
    • https://marosme.ro/hirek/file/98280234592.pdfIn PDF document text
    • http://nessium.fr/userfiles/file/dujizalagalajaxinojox.pdfIn PDF document text
    • http://ezibra.pl/upload//file/paziginatujafarokiwulika.pdfIn PDF document text
    • http://makesrealsense.com/ckfinder/userfiles/files/22452621292.pdfIn PDF document text
    • https://butchercurnow.com/img/shop//contents/64201007808.pdfIn PDF document text
    • http://pumarecovery.com/userfiles/files/sirebepuxosepi.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/8ba93d3f9bb7f9e7c182ad6a51fa9b8a/sijuripu.pdfIn PDF document text
    • http://clearspace-design.com/CKEdit/upload/files/votaf.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ee47c86b25f---30428679834.pdfIn PDF document text
    • https://ratsimae.ee/media/contents/file/46539546098.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/0e33fc98fdcf83b2b9fc075b22391f5c/2599067235.pdfIn PDF document text
    • https://alixdemassy.fr/userfiles/file/wagap.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/91791808097.pdfIn PDF document text
    • https://inncredel.com/uploads/morufifux.pdfIn PDF document text
    • https://erdenetpost.mn/userfiles/files/genujuwixuweredidubadite.pdfIn PDF document text
    • https://colakcivi.com/userfiles/file/56344525261.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=tamil+yearly+calendar+2020+pdf+free+downloadPDF 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_off00010ad9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD9 10920 bytes
SHA-256: 03729ce8bdaa36cb7a831e12be8f510f94d0b395032d711ae04690f0ff96ef22
font_01_sfnt_off00012427.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12427 19056 bytes
SHA-256: 6112a17fa138b861354acafd1b6f6ac0129aa58dc66649969102fdbae76f1848
font_02_sfnt_off0001544f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1544F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1