Malicious PDF — malware analysis report

Static analysis result for SHA-256 798dbcf23f647c06…

MALICIOUS

PDF

79.0 KB Created: 2021-08-03 06:50:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4a8da906578e30f1778b738d840e89d2 SHA-1: 517a23684cb0171ec9310a8dbf14952308788284 SHA-256: 798dbcf23f647c06d1015cf3ddea23634c9e2ac75a062705751ee0e891032bde
156 Risk Score

Malware Insights

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

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload directories and disposable hosting sites. The embedded URLs and the nature of the heuristics strongly suggest an attempt to distribute malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cdc222bcae---64079127911.pdf In PDF document text
    • http://brilspa.ro/userfiles/file///bifexuvuno.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/9e923f35a7dc61f67d967aa1a01c38d6/36986804200.pdfIn PDF document text
    • http://verduciautodemolizioni.it/userfiles/file/pabigemi.pdfIn PDF document text
    • https://transport-vehicules.fr/userfiles/file/77225134336.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/poxiju.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4363386a7---bumuxutapimonug.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/5pfdeuqn2fjpqvjcdqd8dgdc30/52603837952.pdfIn PDF document text
    • http://xn--80aamdqpfpr.xn--p1ai/upload_picture/velivemodesewuvijov.pdfIn PDF document text
    • http://pattarasawat.com/ckfinder/userfiles/files/90196601497.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a8c29eaf7ea---80428090940.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d01b264f395---redelase.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/77vvfc47tn46mgjr5mnpn44rle/vibamivoxo.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bc891aac0ec---xexibutibipifu.pdfIn PDF document text
    • https://tsegypt.com/file/luvojijikajet.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9848c3487---15463356310.pdfIn PDF document text
    • https://almoheetmanpower.com/public_html/userfiles/file/wozolutadesuwetunavuxeku.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae9580a6524---begijukizire.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d5764072386---23728533581.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/2hkfehanj1sj1mmob2t97jlh6a/napapasezika.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160e4212aecf77---namewirinugogukim.pdfIn PDF document text
    • http://tianfonmm.com/d/files/genagax.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/e5538ju35rmb7s84ac10ci4cm8/51173590726.pdfIn PDF document text
    • https://aravlicraft.com/cmsCart//upload/file/nuvikazesude.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=d%C3%BC%C4%9F%C3%BCn+dernek+2+s%C3%BCnnet+m%C3%BCzi%C4%9Fi+indirPDF 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_off0000cb82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB82 10780 bytes
SHA-256: 4d5d54589e1556a7aab7628a5825bca2d5540e5b22ed32551748be0af394d2b1
font_01_sfnt_off0000e426.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE426 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fc38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC38 18808 bytes
SHA-256: d0572a5b24a85e3c5a1f50d739b7aaa837c0aff9d5bbf07c37d2b1b7fd77cbee