Malicious PDF — malware analysis report

Static analysis result for SHA-256 21c1218b8a35f1db…

MALICIOUS

PDF

87.3 KB Created: 2021-09-13 17:27:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: fe4353f7f6ba04aa0e777d1c8f42312a SHA-1: 4a2728db3144911ed3ab25c2c46e62ab7be180f1 SHA-256: 21c1218b8a35f1db78a46a737793ca37ec3724ae9130aa3041ead646b97d5a1e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains a large number of embedded URLs, many pointing to disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://philabc.ru/uplcv?utm_term=soviet+strike+ps1+rom PDF link annotation
    • https://cfaegaianascente.pt/portal/userfiles/files/15726762559.pdfIn PDF document text
    • http://obras.ru/sites/default/files/uploads/16134844907.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/gumapaduno.pdfIn PDF document text
    • http://bitree.net/ckfinder/userfiles/files/68242040396.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3c9519041---54748484314.pdfIn PDF document text
    • http://kiiga.ru/userfiles/file/joxinafelabuw.pdfIn PDF document text
    • http://duepassidalcentro.it/userfiles/files/9303638012.pdfIn PDF document text
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/43486488002.pdfIn PDF document text
    • http://windowsplusllc.com/ckfinder/userfiles/files/wiminalesibineziweraduga.pdfIn PDF document text
    • http://cokhivietuc.webthoidai.com/img-vietuc/files/xebirimemerobugomijafit.pdfIn PDF document text
    • http://ondrejkocar.cz/img/file/nijutabatakawikizedipu.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/037239c6ad10b7dbb817b8fe75da3632/85687116827.pdfIn PDF document text
    • https://fptica.ru/images/file/bulebozefadawovovus.pdfIn PDF document text
    • https://e-ceramika.pl/userfiles/file/17017914152.pdfIn PDF document text
    • http://mayjack.com/upload/files/82299316952.pdfIn PDF document text
    • http://mgbig.com/upload_fck/file/2021-9-12/20210912052756245308.pdfIn PDF document text
    • http://premiumcsp.com/uploads/files/6229237627.pdfIn PDF document text
    • https://stillwaiting.org/userfiles/file/zevijatuxigogiremimuwed.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/tazuridebupitenipufaz.pdfIn PDF document text
    • http://daechienglishpark.com/ckfinder/userfiles/files/dudoneluwanunanipemilek.pdfIn PDF document text
    • http://talesma.com/E/file/457478244.pdfIn PDF document text
    • http://ybshajiang.com/userfiles/file/2021-09-05/210905203248986006s88vbxftvbmf.pdfIn PDF document text
    • http://bmfjhjk.friend-match.com/upload/files/2935403907.pdfIn PDF document text
    • https://rh-h1tapi-turbo.com/contents/files/22874992593.pdfIn PDF document text
    • https://golf-tout-terrain.com/publish/page/file/wapudupamurexemewewe.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/59211169660.pdfIn PDF document text
    • 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_off0000f243.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF243 17672 bytes
SHA-256: 5c65365d75eb245833d201398482ba49b00dfdb37678c4dcd8a5ac7374808b7e
font_01_sfnt_off00012008.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12008 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001381f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1381F 10388 bytes
SHA-256: 2cbd160685470c4eacad7e36879b93359fc689e86c27a7bfb70f38acca84a057