Malicious PDF — malware analysis report

Static analysis result for SHA-256 23ef898418994271…

MALICIOUS

PDF

76.5 KB Created: 2021-08-20 07:03:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 43557f4f8afbe4d33542aa7306ebdc86 SHA-1: 4ac0eb90f844c9fd4ab9f39e5c348703d7ab538a SHA-256: 23ef8984189942714de7cd392e00e2000584054827cc215b4482f9301dd2e2fd
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The file contains a link farm pointing to numerous distinct hosts, many of which are compromised WordPress installations or disposable hosting, suggesting an attempt to distribute malicious content or conduct phishing. The embedded URLs and the nature of the link farm indicate a likely spearphishing attachment delivery vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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 https://cmetrix.net/ckfinder/userfiles/files/78361657736.pdf In PDF document text
    • http://mopron.ru/upload/files/wopeposadugodiku.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd48c9c2e6---ludoluwotijazaforamer.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/ans081mksk66bkb2ho3iauctur/zabekisas.pdfIn PDF document text
    • https://przyklejki.pl/userfiles/9221910011.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/160ac8711c4a04---bopuzanakefefoju.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/b42cc4304a9fc8dd53e7f4960c2453f5/50547940789.pdfIn PDF document text
    • http://filtrydokoparek.pl/img/all/79569732531.pdfIn PDF document text
    • http://malabarisproducoes.com/arquivos/files/2963789582.pdfIn PDF document text
    • http://world-green-hope.com/uploads/files/29638806138.pdfIn PDF document text
    • http://elitaliaweb.it/upload/file/83849273235.pdfIn PDF document text
    • http://aromaonly1.com/yamituki-n/uploads/files/riwevemozebolebazizil.pdfIn PDF document text
    • http://geostudio.eu/userfiles/files/pujesirusulafe.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609430df9765a---86684809872.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160906bb9acb94---nokob.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f2ab7390e00---59096015896.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/7f066c003151143ac29593a5a92e3503/61869707017.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a2c2895d339---jikuvobamunivunudixuzo.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fc1d80378d---7731309491.pdfIn PDF document text
    • http://cnp-inc.com/ckupload/files/43103119932.pdfIn PDF document text
    • https://doublehaircenter.com/upload/ckfinder/files/xukob.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-5-10/20210510112616129797.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/796c8088f91c07d85425854f96854635/2054407588.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=lakshmi+gayatri+mantra+lyrics+in+tamilPDF 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_off0000c859.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC859 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e070.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE070 10588 bytes
SHA-256: 82fd86ed45296877ca4e1bf5c513f9c58efea1daef790dd8c602fbe734e0be4e
font_02_sfnt_off0000f86a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF86A 16460 bytes
SHA-256: 647bc99c18bd1bc3bf498a9a4060950d8d8b8724c240865afed7fad13e8da745