Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9fdbecb909e460c…

MALICIOUS

PDF

80.7 KB Created: 2021-09-14 02:07:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3e8ed6c4e3b2d42b3a185375afb74e75 SHA-1: 9140492191a2bc96a744a8a078bf7baaaaec24db SHA-256: a9fdbecb909e460c68b627b6f70267a16b7fd1146c720d315101774e648b0254
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to domains that appear to be part of a link farm, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or a scam. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 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.
  • 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://hansungid.com/userfiles/file/mamasinenas.pdf In PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/56dflgv8enm87vrv0lkmcttt61/52595085151.pdfIn PDF document text
    • https://ovistar-dz.com/ckfinder/userfiles/files/norefanubogodafub.pdfIn PDF document text
    • https://internationallanguagenavigators.com/media/61672219577.pdfIn PDF document text
    • https://www.info-service.com.tw/plugin/ckeditor/ckfinder/userfiles/files/saxeko.pdfIn PDF document text
    • http://moriefrusca.com/userfiles/files/50437569506.pdfIn PDF document text
    • https://xyoaa.org/sites/default/files/files/13521042037.pdfIn PDF document text
    • https://dianthusindustrial.com/resimler/files/dazababi.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/83b9535d51e33a3236a0acd925508274/54378812471.pdfIn PDF document text
    • https://otterdisplay.com/userfiles/file/3765126859.pdfIn PDF document text
    • http://ruishikaishi.com/upload/content/files/2021/09/20210909102035.pdfIn PDF document text
    • http://nakajima-ya.com/upload/save_image/files/solujujasuluvu.pdfIn PDF document text
    • https://floresdeserrezuela.com/aym_image/files/14896572936.pdfIn PDF document text
    • https://cebrigantina.com/025-CEB/images-editor/file/75783568213.pdfIn PDF document text
    • https://iwanbim.com/userfiles/files/tanejanonaxovem.pdfIn PDF document text
    • http://15881588.com/ckupload/files/24997111832.pdfIn PDF document text
    • http://dvif.fr/userfiles/file/31661902000.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/686012064613800d57d29a.pdfIn PDF document text
    • http://kantipursecurity.com/userfiles/file/52257987326.pdfIn PDF document text
    • https://songhong-thudo.com/img/files/22951536929.pdfIn PDF document text
    • http://hanleyresources.com/images/weminasiva.pdfIn PDF document text
    • http://kelvista.lt/images/files/84628044090.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=davidson+medicine+pdfPDF 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_off0000d550.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD550 18452 bytes
SHA-256: 8fe19a9d255849e07fa0223e351906c35cd485089a4b71bbd06c2f6d30d44ba5
font_01_sfnt_off0001055b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1055B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D72 10604 bytes
SHA-256: e4b510f0e4ded4605bca89a38bfc342901474912c46d1dab293b6083470f5ce8