Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6aab9857b6f3915…

MALICIOUS

PDF

73.4 KB Created: 2021-09-23 05:31:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 0fbabc1c81fb356076852c2b2df1dd67 SHA-1: 5afb3dcae4bebfe0cd3fd6368ab82b3278938bfa SHA-256: c6aab9857b6f39151677522acdafbbeec1357bcf4e6a263d64ece82e5a56dbba
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which are algorithmically generated and hosted on disposable domains, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://synerhu.ru/uplcv?utm_term=hatsune+miku+kagamine+rin PDF link annotation
    • http://fatename.com/uploads/files/202109160110525891.pdfIn PDF document text
    • http://3t-t.com/User_File/UpFile/file/20210901051727_c2VuaXJp.pdfIn PDF document text
    • http://www.terresdescaraibes.fr/file/12659063736.pdfIn PDF document text
    • http://apnschool.in/singhania/downloads/file/36649668286.pdfIn PDF document text
    • http://cuacuongiare.vn/upload/files/pijuwudisalunebavalezuk.pdfIn PDF document text
    • http://autosvilar.com/uploads/ckfinder/files/46186867324.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/92294254349.pdfIn PDF document text
    • https://pacantioquia.org/aym_image/files/fiwavegapipapevu.pdfIn PDF document text
    • https://shreenathtechnologies.com/userfiles/file/31355418201.pdfIn PDF document text
    • http://duet-czluchow.pl/userfiles/file/zuzum.pdfIn PDF document text
    • https://stthomasorthodoxchurchsouthpampady.com/userfiles/file/towuvubojewujujo.pdfIn PDF document text
    • http://www.cerel.eu/images/wyswig_images/file/16823605248.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16142e81d22295---jujuxe.pdfIn PDF document text
    • http://progettarecasa.com/userfiles/files/83178903228.pdfIn PDF document text
    • http://vimar.ua/userfiles/files/48039179566.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c7bff3fff6---53088898478.pdfIn PDF document text
    • http://csaladiegyteruautok.hu/userfiles/files/8614874342.pdfIn PDF document text
    • http://alpes-de-haute-provence.proximeo.com/ckfinder/userfiles/files/28832022406.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-7/20210907175854673653.pdfIn PDF document text
    • https://parlagame.com/calisma2/files/uploads/wovavukewafevivelimuxe.pdfIn PDF document text
    • http://ketoanantamhcm.com/uploads/files/78029714973.pdfIn PDF document text
    • http://ericshartman.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/83248904304.pdfIn PDF document text
    • http://noticiascgnews.com.br/ckfinder/userfiles/files/dovitatizobixake.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_off0000b6fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6FA 10468 bytes
SHA-256: 5ef22d7af06c039c434f38ea228ebd162d2950e68185c4d9e8ef0197bc3cd146
font_01_sfnt_off0000ceac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEAC 18808 bytes
SHA-256: 72c2d932a73dbdc5ee2896b65ac527df6da40df6f06e55eab9344bf12e5c2987
font_02_sfnt_off00010017.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10017 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1