Malicious PDF — malware analysis report

Static analysis result for SHA-256 99a41ba5a89efabc…

MALICIOUS

PDF

70.2 KB Created: 2021-09-18 08:34:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fa8c795ba27e9733bf5406860b0defe0 SHA-1: 6b7007840c057cbd05676210e2e841ab5cff030d SHA-256: 99a41ba5a89efabc2e64b9b9d23533389697b7ffb07fa043c2e6ee989cd1dde8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous links to disposable domains, with a high number of distinct hosts. While no scripts were explicitly extracted, the nature of the link farm suggests an intent to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://thanglong.vn-greenenergy.com/ckfinder/userfiles/files/kobesinur.pdf In PDF document text
    • http://sensor4you.com/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/fefopiwopufipeda.pdfIn PDF document text
    • http://pataibicaj.hu/userfiles/file/20737992653.pdfIn PDF document text
    • http://dream-mebel.com/pic/file/farotazupixudet.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/70894110917.pdfIn PDF document text
    • https://sikdercollegeofpharmacy.com/scp/ckfinder/uploads/userfiles/files/rimakunujepovejevadigif.pdfIn PDF document text
    • http://nature-revive.org/files/file/tamipoxugifikixivuxenav.pdfIn PDF document text
    • https://shipnhanh247.vn/asset/files/16274790617.pdfIn PDF document text
    • http://trubaopt.ru/content/file/17887503404.pdfIn PDF document text
    • http://hydrem.ru/images/file/40154048034.pdfIn PDF document text
    • https://bangprice.com/bangprice.com/beta/cms_image/file/savujirumekupobikarenoxe.pdfIn PDF document text
    • https://euforbiabulgaria.com/uploads/pages/files/gukemepumufasen.pdfIn PDF document text
    • http://ldksolar-officialliquidation.com/userfiles/files/81405853692.pdfIn PDF document text
    • https://g55net.com/webpagebuilder/ckfinder/userfiles/files/18234713787.pdfIn PDF document text
    • http://arndt-fahrschule.de/userfiles/file/48349283822.pdfIn PDF document text
    • http://galsabino.it/userfiles/files/67354107911.pdfIn PDF document text
    • http://www.dilipprabhavalkar.com/images/file/towetowanemisurexetikixa.pdfIn PDF document text
    • http://cukrarska-vyroba.cz/UserFiles/File/metitezaraxixagem.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/23062c9f2a84010e1f4ed73c1726fbce/53861186683.pdfIn PDF document text
    • http://lednotice.com/userData/board/file/dureluraxixokusi.pdfIn PDF document text
    • https://educationindiajournal.org/ckfinder/userfiles/files/26964596417.pdfIn PDF document text
    • http://yves-segers.be/userfiles/files/bifim.pdfIn PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/xajolukerezopofozexef.pdfIn PDF document text
    • http://beerskiboot.de/img/upload/file/zipogaxazukuzogunu.pdfIn PDF document text
    • http://ventmetal.ru/userfiles/files/jamulenavigolonuxovafer.pdfIn PDF document text
    • http://www.dogwoodagility.nl/ckfinder/userfiles/files/28559413189.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=profile+photo+instagram+viewPDF 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_off0000b64c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB64C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE5E 14328 bytes
SHA-256: 14626dfc136e97a23061934c204b3a9d7695f9844ad26b2de9fb5aa39c40017c
font_02_sfnt_off0000f1e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E0 10956 bytes
SHA-256: 13f870275330699d71500c52c7c978a8d9d528a2526b1a8d86b09663f2581cc9