Malicious PDF — malware analysis report

Static analysis result for SHA-256 71b15f3e2a3d46f3…

MALICIOUS

PDF

87.1 KB Created: 2021-09-23 13:49:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: c1147bcf8352e4c56cbca54eb4517fa2 SHA-1: df5403b8759995c7b8fe17e0b8bcca8afaa28da2 SHA-256: 71b15f3e2a3d46f33d0948b7516bb532ef8904fe319c9a2fe680cc71a06c57b0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as a phishing trojan and ML classifiers indicated a high probability of maliciousness. The document contains numerous embedded URLs pointing to link farms, suggesting an attempt to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to exploit PDF vulnerabilities or trick users into clicking malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://daejonggyoyc.com/userfiles/file/20210902151908.pdf In PDF document text
    • https://nuteuit.ro/ckfinder/userfiles/files/92739720588.pdfIn PDF document text
    • https://twinslock.com/ckfinder/userfiles/files/5727341465.pdfIn PDF document text
    • http://whipitleather.com/userfiles/file/garilafosumadiposolefido.pdfIn PDF document text
    • http://sxnqx.org/upload/file/Fl202109011734125533.pdfIn PDF document text
    • http://luberoff.com/userfiles/file/37158558712.pdfIn PDF document text
    • http://righetti-ticozzi.it/userfiles/files/maxowobatesili.pdfIn PDF document text
    • http://excitechem.com/userfiles/file/kagugebe.pdfIn PDF document text
    • http://geluidsadviesnederland.nl/ckfinder/userfiles/files/pikepip.pdfIn PDF document text
    • https://eltdb.com/UserFiles/files/23018561288.pdfIn PDF document text
    • http://prinsart.ro/uploads/files/93656666649.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/t7lpj7vchtnt8la3ud9lnh5lhe/komoxosavedipuke.pdfIn PDF document text
    • https://almavilag.hu/files/files/losepabowixu.pdfIn PDF document text
    • http://na-bytecek.cz/UserFiles/File/81584797247.pdfIn PDF document text
    • https://suacuacuontoanphat.com/upload/files/85506401273.pdfIn PDF document text
    • http://oiseau-bleu-morzine.com/userfiles/file/xeposebix.pdfIn PDF document text
    • http://vigova.vn/Images_upload/files/benakukikax.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/jovujivupojulipowewilu.pdfIn PDF document text
    • http://stomerijindex.nl/images/uploads/72823855898.pdfIn PDF document text
    • http://ud2-140.com/files/jufevex.pdfIn PDF document text
    • https://sukaunited4d.vip/contents/files/zusazuturomikavovovukosi.pdfIn PDF document text
    • http://ninda.vn/userfiles/files/zesarexizapij.pdfIn PDF document text
    • https://abisspaandboutique.com/nbloom/fckuploads/file/dovajafuxesikuxaso.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=hide+root+from+banking+appsPDF 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_off0000eebf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEBF 18100 bytes
SHA-256: ac98ba15cf1b4f3daabc7c5db2d6e3ec6eb38c28951bc9f4475c5cae0860281c
font_01_sfnt_off00011d70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D70 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013587.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13587 11020 bytes
SHA-256: 7904754fd7ac54101a3232a98c3afeb78dba790b95795243b1087969c73c3c9e