Malicious PDF — malware analysis report

Static analysis result for SHA-256 004c3bafa23425e1…

MALICIOUS

PDF

77.3 KB Created: 2021-09-10 10:31:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d73c2afa8565fa05b7537c465a155cd7 SHA-1: a540d81505c551f75738a4cdb2a73c750f0ab366 SHA-256: 004c3bafa23425e1bdc6248e2fc0bc4d534edf6f423ee2c64220392a82f5e1a7
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is a PDF document flagged by ML classifiers and ClamAV as malicious. The SE_FAKE_CAPTCHA heuristic indicates the document presents a fake verification prompt to deceive the user. While no scripts were directly extracted, the PDF structure and numerous embedded URLs suggest an attempt to lure the user to external malicious sites, potentially for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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://kite-surf.sk/files/zopek.pdf In PDF document text
    • http://esistore.com/userfiles/file/22289430967.pdfIn PDF document text
    • http://studiovalecchi.it/userfiles/files/97952068792.pdfIn PDF document text
    • https://taiwan-tiaya.com/upload/tiaya_official/files/kejakuwisijajeb.pdfIn PDF document text
    • https://shian-jin.com/UserFiles/files/vikifolukukomalisikefun.pdfIn PDF document text
    • http://archive-2014.humandoc.pl/attachments/file/29556503512.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/3b3a35624de269d0b2453841b0dfe1a2/33981152324.pdfIn PDF document text
    • https://peoplehelppeople.net/uploads/File/kupumabatasal.pdfIn PDF document text
    • http://doubler-son-capital.com/photos/files/vofivuvexoxugi.pdfIn PDF document text
    • http://phannhan.vn/files/usersfiles/files/kegenupekurigawuv.pdfIn PDF document text
    • https://udruga-invalida.hr/files/ritirokafiz.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/16130a0f16ab93---88540740553.pdfIn PDF document text
    • http://aldobini.it/userfiles/files/gosuwepi.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/32329333908.pdfIn PDF document text
    • http://hansungidschool.com/userfiles/file/19448763482.pdfIn PDF document text
    • https://sportnazona.bg/f/uploads/files/20112405310.pdfIn PDF document text
    • http://jrecchina.com/ckeditor/ckfinder/userfiles/files/1908468018.pdfIn PDF document text
    • http://sxhk365.com/uploads/file///pibamofuvo.pdfIn PDF document text
    • http://gpkoaee.ru/ckfinder/userfiles/files/xawiberijibexewukemopuwiv.pdfIn PDF document text
    • https://smsenerji.com/resimler/files/zujimubemigixudon.pdfIn PDF document text
    • http://daearesort.com/FileData/ckfinder/files/20210906_30717D161B703D15.pdfIn PDF document text
    • https://mvpartners.be/images/uploadedimages/file/puzogurodinasatofitileseb.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/91855595481.pdfIn PDF document text
    • https://yarpaket.ru/userfiles/file/notifa.pdfIn PDF document text
    • http://yigang-lin.com/uploads/files/202109021324548507.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=keyword+density+analysisPDF 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_off0000ca82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA82 10432 bytes
SHA-256: 1b2deedac68e2bdabcff16c893f689d01db8b7a405602671c074e540411e42d2
font_01_sfnt_off0000e255.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE255 17404 bytes
SHA-256: 9e83e728144545a18365eaf718533f3e5dac4c0ae05b773cead825a737969d5e
font_02_sfnt_off00010fa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FA7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1