Malicious PDF — malware analysis report

Static analysis result for SHA-256 f0108ed0780aa427…

MALICIOUS

PDF

79.2 KB Created: 2021-09-10 10:02:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fcb93b348b64ba3be0b97741c47244e5 SHA-1: 94c570167647d7ecffc4001d86032686543fc01b SHA-256: f0108ed0780aa42764b305869620a1b67c7a15486f959fa642a2a2d5d0b6d0fb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains a large number of embedded links, many pointing to unknown or potentially malicious domains, suggesting a link farm or redirection scheme to distribute malware or conduct phishing. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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.
  • 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://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/vobub.pdf In PDF document text
    • http://darec.sk/files/files/79324893274.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/pnumr3hu6lb7gtnr49s2k818rh/31375484203.pdfIn PDF document text
    • https://imagebuzz.net/ckfinder/userfiles/files/84604433176.pdfIn PDF document text
    • http://ud2-140.com/files/nezugigife.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/59203325740.pdfIn PDF document text
    • https://projetounificado.com/uploads/files/66411309151.pdfIn PDF document text
    • https://ontech.vn/images/ckeditor/files/88158079058.pdfIn PDF document text
    • http://doudou.tw/userfiles/files/xiwebutadavilozipepebaz.pdfIn PDF document text
    • http://xn--989ap7r0xbd5x.com/upload/fckeditor/file/koxuzolab.pdfIn PDF document text
    • http://trustycctv.com/ckfinder/userfiles/files/39024402383.pdfIn PDF document text
    • http://kitpaisal.com/mypicture/file/sosajokakazokagin.pdfIn PDF document text
    • http://nhakhoauytinhaiphong.com/upload/files/83958553160.pdfIn PDF document text
    • https://gregoryshow.ru/files/file/18303607662.pdfIn PDF document text
    • http://xn----7sbjvweekof5d.xn--p1ai/files/files/62995798122.pdfIn PDF document text
    • http://flyingwedge.com/uploads/assets/file/febuzosaguwuzepijerefed.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613457af874a2---26085256133.pdfIn PDF document text
    • https://vivekanandbawwa.com/userfiles/file/lonuf.pdfIn PDF document text
    • http://jhdjt.com/images/upload/File/tinopipenuniwo.pdfIn PDF document text
    • https://holcom-solar.com/webroot/img/files/36975932925.pdfIn PDF document text
    • http://lexprikson.com/admin/style/images/userfiles/file/lifoderebikosavozuxibaxox.pdfIn PDF document text
    • https://gaadalagi.com/contents/files/82147527268.pdfIn PDF document text
    • http://jezirka-biobazeny.cz/UserFiles/File/64365427874.pdfIn PDF document text
    • http://balcimimarlik.com/resimler/files/70657062198.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=gothic+bold+font+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_off0000ce92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE92 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6A9 10588 bytes
SHA-256: 773efe43c0d8904246d03ebc1bc8344d9504037cdb8a0ca0810f6924b3b01710
font_02_sfnt_off0000fe89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE89 18672 bytes
SHA-256: fa4b9f553b01ab833316dc6d253f25eced92a7a9e8173f835b0c64b6657d20ad