Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4bdbe31a6d80b6e…

MALICIOUS

PDF

77.7 KB Created: 2021-09-14 09:53:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d57c94985b7d6bbe65c7a66fb48de14a SHA-1: 58071c6e454789d45d83073ac67ae3a64120a1b5 SHA-256: f4bdbe31a6d80b6e4388114d762d72c768f8b1110ef7537fdf5c72026247b2aa
134 Risk Score

Malware Insights

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

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. The PDF contains numerous embedded URLs, many of which are hosted on disposable domains and appear to form a link farm, a common tactic for phishing or malware distribution. The presence of a 'download button' heuristic further supports this. No scripts were extracted, but the overall structure and URL patterns strongly suggest a malicious document designed to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://juentai.com/userfiles/files/69707497481.pdf In PDF document text
    • https://playindiano1.in/ckfinder/userfiles/files/57863047583.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/05ff291f8ccfd15aa20e2d75bac1ef6e/17506471172.pdfIn PDF document text
    • http://landroverbh.com/ckfinder/userfiles/files/81802138303.pdfIn PDF document text
    • https://cincia.ro/ckfinder/userfiles/files/25185587188.pdfIn PDF document text
    • http://umrllc.com/userfiles/files/83075283267.pdfIn PDF document text
    • http://avvocatogiuliani.it/userfiles/files/mikimosowigetagapigumob.pdfIn PDF document text
    • https://fotojursa.cz/userfiles/file/76702379777.pdfIn PDF document text
    • http://fotosvatba.net/userfiles/file/93748350330.pdfIn PDF document text
    • https://buonoantonio.it/userfiles/file/zuzex.pdfIn PDF document text
    • https://yodishit.com/uploads/userfiles/file/sonepogomusunumarivif.pdfIn PDF document text
    • https://imagebeaute.fr/userfiles/file/gasamutudusinemupexaxu.pdfIn PDF document text
    • http://satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/gonasajogimisivorun.pdfIn PDF document text
    • https://mangallagn.com/images/file/8830355611.pdfIn PDF document text
    • http://www.fan-consultants.com.tw/ezadmin/ckfinder/userfiles/files/sogazu.pdfIn PDF document text
    • http://deaprogettazioni.it/userfiles/files/nasisutomemupabibosobu.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/10130512734.pdfIn PDF document text
    • http://speckrepej.com/upload/file/46109105059.pdfIn PDF document text
    • http://turskazka.ru/ckfinder/userfiles/files/22941248679.pdfIn PDF document text
    • http://www.fonfe.com/uploads/files/pufinunakotuwedanabu.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/23279065894.pdfIn PDF document text
    • https://frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/5726589887.pdfIn PDF document text
    • https://fundreamz.com/ckfinder/userfiles/files/zazubazoduxasaxexiwur.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/f7ceaf7622bd04478efe51ba28aae103/gebinib.pdfIn PDF document text
    • https://almudenafernandez.co/ckfinder/userfiles/Files/87275333026.pdfIn PDF document text
    • http://alwaysshine.com/fileimage/file/zokukusa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=os+dialer+apkPDF 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_off0000ca47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA47 18248 bytes
SHA-256: 2a0fe992dd9c9fe63b91d26ae707f685044cd48b5886c330dea14c35ef647bbb
font_01_sfnt_off0000fa24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001123b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1123B 10180 bytes
SHA-256: 0409d69188feb9f0d0172e31a4d8e1e992e76e1ae578f300c6b75702a6b8aa5a