Malicious PDF — malware analysis report

Static analysis result for SHA-256 a388d72fd5aa2904…

MALICIOUS

PDF

69.7 KB Created: 2021-10-02 10:20:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 6158f0569bf7e976a2c8e55ddd682d64 SHA-1: 6b5392bfd630445590e06dfd9062a688724a627d SHA-256: a388d72fd5aa2904a12036043b2e703b662e498352101a4534d2ebba8092c47c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm with numerous external URIs. The presence of multiple unknown reputation URLs suggests an attempt to redirect users to potentially harmful content, aligning with phishing or malware distribution tactics. Although no scripts were explicitly extracted, the PDF structure and URI findings strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://fractinvest.com/uploads/file/bifizevaluroravimujoju.pdf In PDF document text
    • http://thcscatquea.hoaiduc.edu.vn/ckfinder/userfiles/files/suxifu.pdfIn PDF document text
    • https://jagamimpi.info/contents/files/wibinetog.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/26720048076.pdfIn PDF document text
    • https://thepainter.asia/upload/files/87879991469.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/74367681378.pdfIn PDF document text
    • http://brukikostka.pl/uploads/page/file/30217462232.pdfIn PDF document text
    • https://vleek.com/uploads/files/57772993168.pdfIn PDF document text
    • http://seoaudytor.pl/userfiles/file/73479964995.pdfIn PDF document text
    • http://www.skk.com.hk/admin/ckfinder/userfiles/files/2826783866.pdfIn PDF document text
    • http://jiji.pgo.tw/pic/uploads/files/bijiloziwuwusosiwadozupu.pdfIn PDF document text
    • https://studybrilliant.online/app/webroot/img/userfiles/file/zufusosabefutu.pdfIn PDF document text
    • http://luatminhnghia.com/img/files/78178965876.pdfIn PDF document text
    • http://rebeccaosborne.com/uploads/babopazulejapelupofekuf.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16132a33829cb0---62890030464.pdfIn PDF document text
    • http://studioriggio.it/userfiles/files/63394643528.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/6e9c22e0f63b9e3e865fb75ba38c4e91/29100177574.pdfIn PDF document text
    • http://ccadl.com/files/20210907072034.pdfIn PDF document text
    • http://nage-z.com/ckfinder/userfiles/files/7327379479.pdfIn PDF document text
    • http://helloslow.com/data/userfiles/files/60802254387.pdfIn PDF document text
    • http://kmjmt.com/news/upload/file/21092706033703425946nbg5.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/21188468338.pdfIn PDF document text
    • http://millionsdiscount.com/mo_images/files/tarakubixegazav.pdfIn PDF document text
    • http://ooexperience.be/assets/Image/files/xuvoviwavapakinezu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=c%2B%2B+pointer+to+objectPDF 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_off0000b0ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0AB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c8c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C2 10292 bytes
SHA-256: eab86953b2a8f949936b2e5ff93b071c1857b37324e929797132f0787579210d
font_02_sfnt_off0000dfcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFCC 16332 bytes
SHA-256: 0986c4967a21b74c2f0f40a1f7c269510e1abe8ea9f69d791d3b34d3130cef63