Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81f4e485d890eb9…

MALICIOUS

PDF

73.4 KB Created: 2021-09-18 07:10:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f0ff9fe991c948c52b3109b14ca98f3f SHA-1: 52be360f1887b462043a343d30e4490c884b5427 SHA-256: a81f4e485d890eb945abf5ac70b3b26ccd99dea2a114101da79201d3ded53ccd
174 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and a high-risk heuristic firing for a random URL link, indicating it's designed to redirect users to malicious content. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports its malicious nature. The embedded JavaScript likely facilitates the redirection to the identified malicious URL, serving as a lure for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://vayamcs.com/content_files/files/rakavekepiwaxus.pdf In PDF document text
    • https://people11people.com/uploads/File/69653215230.pdfIn PDF document text
    • http://omni-links.com/images/blog/file/98380413774.pdfIn PDF document text
    • https://typeone.com.my/ckfinder/userfiles/files/91890436218.pdfIn PDF document text
    • https://moraure.net/js/ckfinder/userfiles/files/wuxurexozusobokivoxi.pdfIn PDF document text
    • http://klasykarozrywki.pl/public/images/fck/file/43660660714.pdfIn PDF document text
    • https://basealimentare.it/webroot/files/fck_uploads/File/54792701004.pdfIn PDF document text
    • http://nattukoottam.com/userfiles/file/38631716542.pdfIn PDF document text
    • https://sanaspinler.com/calisma2/files/uploads/zanabapali.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/tekif.pdfIn PDF document text
    • http://www.moyekolodin.com/files/godulaxudi.pdfIn PDF document text
    • http://sisparts.pl/zdjecia/fck/file/26474676930.pdfIn PDF document text
    • https://takitech.hu/userfiles/file/gupuzepunufatitojamakogu.pdfIn PDF document text
    • https://mcq.bmtinhoc.vn/InteriorWeb/images/images_news/files/28720109805.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/0e68fd659438deb235af74db3e2d2969/85897565719.pdfIn PDF document text
    • http://goldendoodlesofthesierranevadas.com/userfiles/file/87468564962.pdfIn PDF document text
    • https://bdblue.com/ckfinder/userfiles/files/wasenid.pdfIn PDF document text
    • http://automotiveenergy.cz/userfiles/file/27319870526.pdfIn PDF document text
    • https://hnhaa.com/userfiles/tnejp/files/87233465739.pdfIn PDF document text
    • https://qkon.ca/images/file/53376278865.pdfIn PDF document text
    • http://logiccpacma.com/ckfinder/userfiles/files/77776346262.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/73972b6f1222c383340c888e4963b43c/46481431542.pdfIn PDF document text
    • https://permargi.com/files/galeria/files/48500466952.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=composite+number+meaningPDF 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_off0000bae1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAE1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d2f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2F3 17388 bytes
SHA-256: 38639c06899df63169a66094f5d3bf4f9c5a98e7576c45593f3ee3f88b188e8d
font_02_sfnt_off0000ff8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF8A 10820 bytes
SHA-256: 6cf1346327298c5b251e9b4fda75ab309fc05de1168d3cc4fd39a6d8ddb5f633