Malicious PDF — malware analysis report

Static analysis result for SHA-256 677d911a966763a3…

MALICIOUS

PDF

88.5 KB Created: 2021-10-06 10:48:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6b61ce937d8a267bb455d9f53cb360e9 SHA-1: b53d4a3576a61a63df9494b641f082fd51842fe7 SHA-256: 677d911a966763a3a922ff5855a19bcf971f6ffca3f29b2b1d448ffbd7740478
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of multiple distinct hosts and the use of 'utm_term' parameters suggest a campaign designed to attract traffic through SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://synerhu.ru/uplcv?utm_term=lab+puppies+harford+county+md
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7141cbc28---56791584783.pdf
    • http://smelawservice.com/file_media/file_image/file/79028057343.pdf
    • http://ddservice-bmw.pl/userfiles/file/30277543097.pdf
    • http://jlssj.com/qianzi/upfile/case_editor/file/zemoborojokenugedazidi.pdf
    • https://fgcrubochi.com.ng/ckfinder/userfiles/files/minodidosuvikegunap.pdf
    • https://www.fangjin.org/ckfinder/userfiles/files/41475392301.pdf
    • https://www.restaurant-latableedevercel.com/ckfinder/userfiles/files/mekikaxidabujawojam.pdf
    • http://sochi-polyana.com/ckfinder/userfiles/files/3070201601.pdf
    • http://aodaiminhhanh.com/app/webroot/uploads/files/12759945139.pdf
    • https://selispin.com/calisma2/files/uploads/99130702239.pdf
    • http://odesignlab.ru/admin/ckfinder/userfiles/files/66088603246.pdf
    • http://cupta.org/userfiles/files/20210901073637.pdf
    • http://odnoklassniki-files.ru/images/uploads/files/89454016943.pdf
    • http://moderncarrent.com/user_img/files/mupaxugozewoselutituxu.pdf
    • http://christopherspubandgrille.com/userfiles/files/lozevewinis.pdf
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16135696f1398d---tegujazowixopazurosujali.pdf
    • http://ballmillfactory.com/d/files/3139328666.pdf
    • http://3bbb.fr/ckeditor/upload/files/92329757038.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1614c492a0ef84---kodasakegerol.pdf
    • http://marcus-1.com/FileData/ckfinder/files/20211004_900E4275A4225637.pdf
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/32570490494.pdf
    • http://www.sas.edu.mn/ckfinder/userfiles/files/perituganemu.pdf
    • https://airflow-skateboards.com/upload/file/96507449635.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e8e2.bin
b2484c19b60f0605922e72b4b3c3d37ecb74f760e6397717aea3072296970a2a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E2 21208 bytes
font_01_sfnt_off000120d2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x120D2 16792 bytes
font_02_sfnt_off000138e9.bin
8ae236fc1976de9de6a142edf34def8dbec1b9b6cfbccb15786a8539f7bee6ad
pdf-font-stream PDF embedded font (sfnt) at offset 0x138E9 11152 bytes