Malicious PDF — malware analysis report

Static analysis result for SHA-256 9617ba81f9ea2c5c…

MALICIOUS

PDF

70.0 KB Created: 2021-09-26 08:19:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a56d361c58bd2cea54469c255e396f94 SHA-1: 756a86ed6f5f6292a70305dda9976dc5c5228179 SHA-256: 9617ba81f9ea2c5c844266e3cecfe74f332a6a214fdc95bb46229bcad908b2c2
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains numerous links to external PDF files hosted on various domains, many of which appear to be disposable or low-reputation. The heuristic 'PDF_RANDOM_URL_LINK' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest this is a link farm designed to distribute further malicious content or phish users. The presence of multiple external links indicates an attempt to lead the user to a malicious resource, likely for exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://vagtteam.com/userfiles/Files/nopijukewurufawe.pdf In PDF document text
    • http://weiken-rc.com/upload/files/bivagekemedowasag.pdfIn PDF document text
    • https://coffeetuanvang.com/Images_upload/files/52282507138.pdfIn PDF document text
    • http://thailaundry.com/imgUpload/files/90517888961.pdfIn PDF document text
    • http://hhoasis.org/app/webroot/img/fck/file/gukim.pdfIn PDF document text
    • http://geo-equipe.it/userfiles/files/weronunanarifop.pdfIn PDF document text
    • http://muszempilla.com/files/file/70368736278.pdfIn PDF document text
    • http://www.bash.cl/media/file/gizupos.pdfIn PDF document text
    • https://foodvellythailand.com/upload/files/64319961366.pdfIn PDF document text
    • http://tecresconsolidamentorestauro.it/fck_data/file/levawufawa.pdfIn PDF document text
    • https://showdetango.com/bafa/userfiles/file/wawalazosevuvarur.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/94703328291.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142dda078a82---49977504649.pdfIn PDF document text
    • http://clinicaveterinariacittadivignola.com/userfiles/files/85662316287.pdfIn PDF document text
    • https://keyword-lda.pt/site/upload/file/69498710247.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/42a47a12d72dca6f078c0372506df5bb/mowuzesukakirexav.pdfIn PDF document text
    • http://studiosaletta.it/userfiles/files/49984351014.pdfIn PDF document text
    • http://hotel-ambassador-nice.com/upload/files/powipibizinaranam.pdfIn PDF document text
    • http://innospectrum.eu/hirlevel/file/31739539868.pdfIn PDF document text
    • https://perfectprojects.ro/userfiles/file/movasugusebimamuxa.pdfIn PDF document text
    • https://m-audio.vn/img-m-audio/files/45230964055.pdfIn PDF document text
    • https://bem-sa.com/img/file/19772586242.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=carrom+board+game+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_off0000afa8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFA8 10488 bytes
SHA-256: 9c9a74a9451e0ee0057e92256cdf574c73d3efa3f39347eafd04dcc8d3941f5c
font_01_sfnt_off0000c70c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC70C 17252 bytes
SHA-256: 5faed34daad004b4cb5a36045ff537bb11315ed712a00ffb60661a56a122356e
font_02_sfnt_off0000f2de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1