Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4c834ba531cd29b…

MALICIOUS

PDF

81.5 KB Created: 2021-09-12 03:26:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 8c0982162b05f4ce8f0a002ebb78312e SHA-1: 2a155757c7a3369b478e870ef120b6f5fc8d7196 SHA-256: a4c834ba531cd29bade255eb3a33a59c14ee7125b23ceed010142021f880a99e
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised websites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The PDF structure and embedded links are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613341d672967---61595797329.pdf In PDF document text
    • http://aaykpn.com/uploads/editor/files/vazusirukupikilupakigimu.pdfIn PDF document text
    • https://073741256.com/uploads/files/202109021723278175.pdfIn PDF document text
    • http://www.eatvirukai.lt/uploads/files/lejutedoza.pdfIn PDF document text
    • https://bimore.vn/webroot/img/files/1876633764.pdfIn PDF document text
    • http://hicoweld.com/shop/fck_file/file/74553943142.pdfIn PDF document text
    • http://zl369.net/userfiles/file/97728912111.pdfIn PDF document text
    • https://clubesolbra.com/uploads/files/86173505549.pdfIn PDF document text
    • http://karpatskiles.ru/store/files/givalewuzopopomojojeme.pdfIn PDF document text
    • http://palirna-frydek.cz/uploaded/file/xokejurakafovebaluv.pdfIn PDF document text
    • http://studioghittigargnano.com/userfiles/files/sowalegiziraserim.pdfIn PDF document text
    • https://fengshan-zhennangong.org/upload/ckfinder/files/55426488766.pdfIn PDF document text
    • http://weighlessthisyear.com/ckfinder/userfiles/files/85889725839.pdfIn PDF document text
    • http://shceping.com/upFile/photos/2021-9/file/tilavaxetabironelezafeme.pdfIn PDF document text
    • http://artpolinakuzina.ru/pict/file/81951309997.pdfIn PDF document text
    • http://avtokit116.ru/!upload/files/wuximumijexazikutaliwewiz.pdfIn PDF document text
    • https://artenika.pl/fck/file/dadabiwujoj.pdfIn PDF document text
    • https://vettercycles.ch/userfiles/files/gaxuxabekasap.pdfIn PDF document text
    • http://heaig.org/editor/ckfinder/userfiles/files/zanirafemazalapazizewi.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16139eac33619d---nivorelajokuzivi.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/16138bca18271a---19229836797.pdfIn PDF document text
    • https://sluganarodu.org/userfiles/files/79813162755.pdfIn PDF document text
    • http://zs-oilfieldequip.ru/d/files/kinetugalifuvokekuxagep.pdfIn PDF document text
    • https://hsdinstruments.nl/uploads/files/loduzajuzegogatobovusolu.pdfIn PDF document text
    • http://dunakeszi.varosom.hu/userfiles/files/89988403007.pdfIn PDF document text
    • https://digireg.nz/upload/8929400173.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=friv+old+games+2017PDF 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_off0000ce78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE78 21868 bytes
SHA-256: 835bd2bdf3ff623293e3e91fe32964eb9ff353e53d3ed8ed1ad8c5c8a390e625
font_01_sfnt_off000107bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107BD 10776 bytes
SHA-256: 5e499c1ff0898b49009392d65500b355b204e4b40baa3f8e5a92064cf02aab02
font_02_sfnt_off00012076.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12076 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1