Malicious PDF — malware analysis report

Static analysis result for SHA-256 951c87add21e2f5a…

MALICIOUS

PDF

88.5 KB Created: 2021-07-07 01:31:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 865d9310d7d6fd63e2801a86c59fddfd SHA-1: 70646342a5976f7ae61fbc84131bba6e8f2b6392 SHA-256: 951c87add21e2f5a4eec6553e504f301cb60d72cd7a17a60825aacd9f4afcbed
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous external URIs, many pointing to compromised CMS uploads or disposable hosting, suggest a link farm designed to redirect users to malicious content. The presence of embedded JavaScript, though not directly analyzed for specific actions, is commonly used in PDFs to initiate malicious redirects or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://irlanc.ru/uplcv?utm_term=from+excel+to+pdf
    • https://samoinstitute.mn/uploads/assets/file/75376213843.pdf
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/gpc9thnn51gke2p0j9echgpbf9/lelunesiwulusanudusit.pdf
    • http://parvazyab.net/basefile/api203/files/tazupeli.pdf
    • http://nw-line.ru/generic/uploaded/wulimafeketa.pdf
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/na3amfdbqrrp3f94l9e31j2kc8/5960323648.pdf
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608d52a4e3500---90373780757.pdf
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cca8267b0e---xuxupuwabupusanipixe.pdf
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/a25abe3378dc588bffdcfb923ea87179/kuravovefapuwejixukababow.pdf
    • http://arslanemlak.com/E/file/36292526635.pdf
    • https://realxenon.ru/uploads/files/92701497013.pdf
    • http://ecohort.com/userfiles/files/tapoveronugili.pdf
    • https://sip7.pl/autoinstalator/sip7.online/wp-content/plugins/super-forms/uploads/php/files/340536b4479f2ce8a71ee9e64dd25c67/81635603061.pdf
    • https://hzautomatisering.nl/userfiles/file/84704071872.pdf
    • http://waterreducer.cn/d/files/37279516359.pdf
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/ck7rs2bdid952jdsphbvho07mf/1383200322.pdf
    • https://mnlex.it/file/26752548774.pdf
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/7152702cd15bff0660a3d6147c037296/topuzedozavidumali.pdf
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/16078392fdb122---sumakijeji.pdf
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/160dccd9446987---13678465368.pdf
    • https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/e02c163d34eaba60633ae65c324397e5/316058611.pdf
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/2f1a8d1c2ff83cafe9d3ef6340eac482/bajitibuzawomef.pdf
    • http://alphasigmaoverseas.com/userfiles/file/fobijegekujigeladavojum.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b6bcd86c47---sixono.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_off0000f975.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF975 16792 bytes
font_01_sfnt_off0001118c.bin
b39f9b8ae4e5054860a0c90db03a59c1f01c4869c517bafe607beefb871b449b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1118C 10336 bytes
font_02_sfnt_off000128db.bin
12ff55a16d8a70f83f7557eae07a61c84fc6584e354482c39ee6669184257252
pdf-font-stream PDF embedded font (sfnt) at offset 0x128DB 16988 bytes