Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cb688a4999c21c9…

MALICIOUS

PDF

76.3 KB Created: 2021-06-24 10:36:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 8a8669f95263389d1482b13f40f9d662 SHA-1: d809c46150b07ab1ddda28eaa61cd46d0103805f SHA-256: 8cb688a4999c21c96bac4982f97fe40faea6f252ab2a6e0107ffcbaf526d9e1d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting it's used to distribute further malicious content. The document body, though heavily garbled, appears to be an attempt to disguise the file as a programming solutions manual, a common lure for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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 http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081e75e0a308---kilagomuvumawawamevekodoz.pdf In PDF document text
    • http://albino-pitti.com/pub_img/file/75062846675.pdfIn PDF document text
    • http://metabolit-plus.ru/files/file/75242222017.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d6c4c0e5d4---72872778203.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/5urrig8fi1d8oke1m5hkca8n52/figumapow.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/a9ed8194d075da57bab4b0fe5bc6687d/41790330393.pdfIn PDF document text
    • https://diaochue.vn/userfiles/file/20636754085.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/mpnlnppsp9hb4fcc7i4imhrikm/89287519194.pdfIn PDF document text
    • https://taperagi.com/contents//files/tobamoj.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609a5ea35bf5f---17382184254.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f093ee9ffa---roratipo.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607985057a7a7---96466130519.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/255bbe35a8d093127a37c5ae17decfe9/lifenimo.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c8eb4226bbe---ziseg.pdfIn PDF document text
    • http://ippon.lv/uploads/File/fopuwax.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072d2ec015a1---jinewokagilezubapidag.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=java+how+to+program+9th+edition+solutions+manualPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e5bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5BB 5672 bytes
SHA-256: 7e13367aacb08b59deae643dd318626b557037cd06981c3e71eef6d4382e1d18
font_01_sfnt_off0000f8fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8FC 12756 bytes
SHA-256: aa3271d162b7652352379afd8cecef4202675632ca0dddc4c57454d0bb40208f