Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8c0c18b093072ad…

MALICIOUS

PDF

80.3 KB Created: 2021-09-19 23:31:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ef417e549b0a4b1e35b00b31fda38867 SHA-1: 1467b584e8a1c66be55bef763833feba89fe0520 SHA-256: d8c0c18b093072addb05b58ada4a407529f9ad87b9be147804ad2a86e1124e96
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous external URIs pointing to PDF files hosted on compromised WordPress sites and disposable domains. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests a distribution mechanism for further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://oniceh.ru/uplcv?utm_term=8+letter+words+with+c PDF link annotation
    • http://hnkingdee.cn/Files/file/2021919235325.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1613de945c55e1---26981723485.pdfIn PDF document text
    • http://hublihorse.com/uploads/userfiles/files/fijejurofofurugixenepu.pdfIn PDF document text
    • http://ranjitabiswas.com/userfiles/files/9196759539.pdfIn PDF document text
    • http://zatexpress.com/upload/userfiles/files/kilojetudidedekanuboxubo.pdfIn PDF document text
    • https://escaletravel.com/userfiles/files/witomadunodere.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/c2f029c03318542383c6c71790bed237/wojinufuvubekagudusimore.pdfIn PDF document text
    • http://pekbdt.com/filespath/files/20210909152056.pdfIn PDF document text
    • http://chemicalengineers.ie/images/vufodojurebadofol.pdfIn PDF document text
    • http://montex.pro/uploads/userfiles/file/texalumij.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/3842c35043feef352c706d61f36ed694/41896721242.pdfIn PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/qhjge55drv833vcfutq4ded5h5/kasukenawanopedididazimi.pdfIn PDF document text
    • https://emotionalgift.youngzonejewelry.com/ckfinder/userfiles/files/10999267936.pdfIn PDF document text
    • http://iraneto.com/basefile/iranetocom/files/47104523746.pdfIn PDF document text
    • http://burbank.kopanramen.com/uploads/files/jiwelimatobitaxebul.pdfIn PDF document text
    • https://owop.challengersports.com/userfiles/files/45889531769.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/161441deca865c---50975088940.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/24455161852.pdfIn PDF document text
    • https://aluminiosarla.com/userfiles_arla/files/26752544399.pdfIn PDF document text
    • http://captainkillmite.com/uploads/files/202109021537415737.pdfIn PDF document text
    • https://ccaquebec.com/userupload/files/bamiwa.pdfIn PDF document text
    • https://burgaseguros.com/userfiles/file/vamelisefede.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_off0000d4f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4F4 18292 bytes
SHA-256: 855215165c3bef8c915126e5f6941c48e84d746c49deb54fd249f7043f0eeff4
font_01_sfnt_off000103b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B3 10400 bytes
SHA-256: f488842ebe819ee665b6e8c7511d423aa62fdc8641013533ebc9166cdc7dcea3
font_02_sfnt_off00011b69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1