Malicious PDF — malware analysis report

Static analysis result for SHA-256 28da871c1345a83f…

MALICIOUS

PDF

81.1 KB Created: 2021-09-19 00:04:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4188bb0f5f919a393c2302983aead55e SHA-1: 8dd458fa1b8c53176ffaf3269e7f4c02b21803a3 SHA-256: 28da871c1345a83f3b8f34f4198205d655d6a22546a1a2a11662030ff4defd24
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or redirection scheme. The presence of external URIs and the nature of the heuristics point towards an attempt to direct the user to malicious external content, likely as part of a spearphishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://korsorlampang.net/user_img/files/jonisujifizabapepukejon.pdf In PDF document text
    • http://taxplus.in/images/contentimages/files/22470404447.pdfIn PDF document text
    • http://diamant-x.sk/UserFiles/file/kodikevujukugodasetek.pdfIn PDF document text
    • https://dp-engineers.com/admin/userfiles/file/3666056817.pdfIn PDF document text
    • https://totalmediasolutions.ae/ckfinder/userfiles/files/24679834253.pdfIn PDF document text
    • http://prtourusa.com/FileData/ckfinder/files/20210914_6508E551C51AA8E7.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/52559935992.pdfIn PDF document text
    • http://ashioke.com/images/library/File/59427171690.pdfIn PDF document text
    • http://dkmmotor.com/files/userfiles/file/zoxoduranajof.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/348d96da6bed6cb7567e5ec275573bcb/rojewasalazefejupigusasu.pdfIn PDF document text
    • https://cowik.pl/upload/dawolupisesutevadeda.pdfIn PDF document text
    • https://artbynela.com/uploads/file/39578961352.pdfIn PDF document text
    • http://we-women.de/default/files/uploads/file/kumivaso.pdfIn PDF document text
    • https://doublehair.center/upload/ckfinder/files/kababonumiwogezabewanipux.pdfIn PDF document text
    • http://leylatoprak.com/userfiles/file/nikibuzusekin.pdfIn PDF document text
    • http://phunphu.com/userfiles/file/96936869691.pdfIn PDF document text
    • http://longarmacademy.net/fckeditor/userfiles/file/13778818842.pdfIn PDF document text
    • http://magogaralbamoble.com/galeria/files/gusamebavup.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613d45f941fbf---78518497910.pdfIn PDF document text
    • https://daotaolaixesontay.com/uploads/file/xifadugiput.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/bajinuzuso.pdfIn PDF document text
    • https://delphin-restaurant.com/ckfinder/upload/files/kivudarumezusetunagi.pdfIn PDF document text
    • https://floraplant.gr/FCKeditor/userimages/file/39984863327.pdfIn PDF document text
    • http://n3ss.ro/ckfinder/userfiles/files/30163981728.pdfIn PDF document text
    • https://dailyhondaotomientay.com/upload/files/fovinuxovodixusaxul.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=adjust+screen+sensitivity+s8PDF link annotation
    • https://lapdonline.org/file/45877762183.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_off0000d743.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD743 10636 bytes
SHA-256: 6be790deac9e23318c2187c0f97a7f4433d9f876edfca3fd59ff35c2e1632dbd
font_01_sfnt_off0000efb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB9 18308 bytes
SHA-256: fd46fc729dcc337b91fdfb9836ef84781e77b86d8a17753a73d8a983d3b3123c
font_02_sfnt_off00011e5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1