Malicious PDF — malware analysis report

Static analysis result for SHA-256 aef2666c4d9f4be9…

MALICIOUS

PDF

70.0 KB Created: 2021-09-20 03:47:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 77cc3f5c930bd94b8e7795eb50c5ec18 SHA-1: 3608a194486c0e9bce00f51b5adf93b729d1c6a8 SHA-256: aef2666c4d9f4be91dc03fe978bce284c1600ed1e01e8da03b35799b482f829e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ClamAV as Pdf.Phishing.Trojan. It contains numerous links, many pointing to disposable domains, suggesting a link farm or phishing lure. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://udmvdpo.ru/images/files/53414360132.pdf In PDF document text
    • http://innobiztour.com/FileData/ckfinder/files/20210905_F9445CD9B3CD512A.pdfIn PDF document text
    • http://qdjshg.com/files/file/28641400345.pdfIn PDF document text
    • http://hylimusic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/tafalawupo.pdfIn PDF document text
    • http://clairvoyantinfotech.com/demo/images/siwifixotes.pdfIn PDF document text
    • https://alwaysthesame.pt/site/upload/file/95553155584.pdfIn PDF document text
    • https://landtop.com/filespath/files/20210917051658.pdfIn PDF document text
    • https://essaidafm.com/uploads/FCK_files/file/58686273899.pdfIn PDF document text
    • http://skalamatbaa.com/userfiles/file/ximamusewam.pdfIn PDF document text
    • https://doina.md/fckeditorfiles/file/jerosumazakidax.pdfIn PDF document text
    • http://studiopetrilli.it/userfiles/files/zokutaliji.pdfIn PDF document text
    • https://immsac.pe/sgi_userfiles/userfiles/files/xevufufeperetofolew.pdfIn PDF document text
    • http://grgct.com/ckfinder/userfiles/files/nodaditisiraxenogod.pdfIn PDF document text
    • http://santabruna.cl/upload/file/30517179324.pdfIn PDF document text
    • https://rawoctane.com/uploads/file/bamif.pdfIn PDF document text
    • https://bimstudioinc.com/media/files/sifetevurujakujifilodete.pdfIn PDF document text
    • https://rpdev.org/ckfinder/userfiles/files/32655981424.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/nudevepani.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/55463806571.pdfIn PDF document text
    • http://aeklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/63062352710.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/bf46d1460476d80e712756127f5818ac/78343182748.pdfIn PDF document text
    • http://www.pataniforum.com/admin/jquery/ckfinder/userfiles/files/20757728125.pdfIn PDF document text
    • https://smsenerji.com/resimler/files/5718139369.pdfIn PDF document text
    • http://dataction.org/demo/dataction/media/95291058620.pdfIn PDF document text
    • http://prime42.ru/userfiles/files/64179193624.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=fortnite+free+redeem+codes+2020PDF 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_off0000b331.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB331 15584 bytes
SHA-256: f33d0cce0660d8ba6a383cf4263e29558cd8341f9a889e027d2d276831845701
font_01_sfnt_off0000da16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA16 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f22d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF22D 10648 bytes
SHA-256: ce86d0cc2d9caf8205b9ba3206f453018264fde1a79decbf43e516d8953c2473