Malicious PDF — malware analysis report

Static analysis result for SHA-256 0bbd68820ab21ca2…

MALICIOUS

PDF

81.0 KB Created: 2021-09-20 12:56:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fea2e642c2c7bc396aa46a222f9c2383 SHA-1: f7d01121e1e1fb37467a5598e20afe605c0d7a55 SHA-256: 0bbd68820ab21ca2adafbf04f700c98f6c32a409c07ea6fbc685145f3d402c65
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm directing users to multiple external URLs, several of which are hosted on compromised WordPress sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a vehicle for the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://vietnam-pump.com/userfiles/file/wujosojesepikiduxos.pdf
    • http://xn--b1akwe.xn--p1ai/userfiles/file/49127046302.pdf
    • http://anduong-nhatthanh.com/uploads/news_file/rezetobamaridopazopaja.pdf
    • http://dentali.cz/files/files/jizix.pdf
    • http://www.ondebiz.com/userfiles/file/wulon.pdf
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/1d4a6a3892a0d23dbecaee5245320998/xogexeviwesimomusovul.pdf
    • https://paulogomeslda.com/userfiles/file/taroredixijijuzewetesipev.pdf
    • https://karlholmbygg.se/UserFiles/files/13263847916.pdf
    • http://elitvorota.ru/f/file/34851004519.pdf
    • http://solarexperten.ch/fckeditor/editor/images/file/63078583857.pdf
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/6c49abdd9330ec203f7aff0128161f23/50169333593.pdf
    • http://studiotecnicomancini.eu/userfiles/files/venegaroga.pdf
    • https://iohrp.org/f_files/files/88093422552.pdf
    • http://qishuochem.com/siicea/userfiles/file/nolub.pdf
    • http://www.accl-calibration.com/login/ckfinder/userfiles/files/dowivemaromuvivupobonepiw.pdf
    • http://portamarioarchitetto.eu/userfiles/files/kitemizogimosad.pdf
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/161442cd5bf256---59017244638.pdf
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141127c91c25---79806783821.pdf
    • https://pnp-studio.com/fckeditorfiles/file/mutegenipopetadegake.pdf
    • http://bikaji.zohukum.com/ckfinder/userfiles/files/93663998499.pdf
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142239133d71---31752576900.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613f0bdad93c1---40906613048.pdf
    • http://hanasushi6.com/uploads/files/74302635902.pdf
    • http://bibliotekaludwin.pl/img/upload/files/7282634920.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=redmi+note+8+hidden+apps
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6ab.bin
b426553fc459a5ffea71cdb3f9f707d05a8dea763c8ffe6e9ad55ef7aefdf2e8
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6AB 10764 bytes
font_01_sfnt_off0000ef3e.bin
0bdcc4489c431a3ed644d70e169205b07613d92c0ad97fe9c7367895f5f66232
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF3E 18360 bytes
font_02_sfnt_off00011eb2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EB2 16792 bytes