Malicious PDF — malware analysis report

Static analysis result for SHA-256 a273f0e98d1fb531…

MALICIOUS

PDF

68.8 KB Created: 2021-09-25 07:14:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b5f87cd3a370e495f4bbc5e87467a95e SHA-1: 672dada9a2baa006262da947c9d7a112525e2d93 SHA-256: a273f0e98d1fb531ca3e2a18b39091aa8e341ce86ba1f53c95d81f34d50921eb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous external links, many pointing to disposable domains, suggesting a link farm or redirection mechanism. While no scripts were explicitly extracted, the PDF format often utilizes JavaScript for malicious actions, and the presence of external links strongly implies an attempt to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://cleaner.pl/userfiles/file/likivoboveg.pdf In PDF document text
    • http://laboratoriologos.it/userfiles/files/sejazepilo.pdfIn PDF document text
    • http://decaiyun.com/upload/file/210914154957109204y6mx0mma25z5.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///96720630292.pdfIn PDF document text
    • https://karlschool.org/uploads/files/202109031636453095.pdfIn PDF document text
    • http://cen7dias.es/userfiles/files/64572767111.pdfIn PDF document text
    • https://kominove-centrum.cz/media/files/file/vatojupowuxisivibep.pdfIn PDF document text
    • https://minhkygroup.com/luutru/files/69083174290.pdfIn PDF document text
    • http://ineke-ott.nl/keramiek-beelden-imagesfile/duguf.pdfIn PDF document text
    • http://acevina.com/webroot/img/files/63819923145.pdfIn PDF document text
    • http://ctcinsulator.com/uploads/file/84085581871.pdfIn PDF document text
    • http://www.anapharmata.hu/ckfinder/core/connector/php/files/44764004067.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142360f31baf---5802288445.pdfIn PDF document text
    • https://bloomeng.com/uploads/32095301289.pdfIn PDF document text
    • https://ruiguoex.com/upfile/files/2021/09/23/50907260209.pdfIn PDF document text
    • http://www.derbysignandgraphics.com/uploads/file/kuvekaneveweviwe.pdfIn PDF document text
    • https://kaimano.it/file/60614851058.pdfIn PDF document text
    • http://vanxuantravel.com/upload/files/15409835431.pdfIn PDF document text
    • http://studiotravenzolo.it/userfiles/files/kaxekikisu.pdfIn PDF document text
    • http://cleanyachts.it/writable/public/userfiles/file/43788773300.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/jixevabazu.pdfIn PDF document text
    • https://venusnvs.com/userfiles/file/61961275192.pdfIn PDF document text
    • http://autoset66.ru/admin/ckfinder/userfiles/files/55431347943.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb81e869fa---xozavejigumezo.pdfIn PDF document text
    • http://crocepadrekolbe.it/userfiles/files/74648243340.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=pokemon+heartgold+events+codesPDF 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_off0000af1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c72d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC72D 15120 bytes
SHA-256: b9f40be1be42b522f0eab4a90d61d99337a2b926cb409d85b3171e44b35c720e
font_02_sfnt_off0000ece7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECE7 10884 bytes
SHA-256: f0508687421d8596b0b11c102ecd1a29c7fd94723e95f6178520f7e9480f2abf