Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4da6d88f5ab0faa…

MALICIOUS

PDF

72.4 KB Created: 2021-09-21 00:07:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b3dc3e237619c8ddef6519f108a8db85 SHA-1: c2e44937a5365ac15bb5cde4748ea2ca05bbf2bf SHA-256: e4da6d88f5ab0faacb3ad27cfd0e6bd5b9f5fcb2bbecfad77323ddb001342a3c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of links, many pointing to compromised WordPress sites and disposable domains, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to phishing sites or download further malware. No scripts were extracted, and the document body was unreadable, but the link farm heuristic is sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/0fcc82e982504b961f20bf5bb9fedc60/gumubegirevotaketoxu.pdf In PDF document text
    • https://mtmnetwork.net/uploadEditor/files/mulutagez.pdfIn PDF document text
    • http://obraz-tlt.ru/userfiles/file/piluledu.pdfIn PDF document text
    • http://lawyermo.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/75784009276.pdfIn PDF document text
    • http://dd-eng.com/files/files/potadisedonoker.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140fde4af520---23294704991.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16143d945577d5---38935925977.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/file/24998732374.pdfIn PDF document text
    • http://vako.vn/app/webroot/uploads/files/4428248907.pdfIn PDF document text
    • http://ajk-opakowania.eu/upload/fck/file/55229668609.pdfIn PDF document text
    • http://kisito.com/userfiles/file/8692990804.pdfIn PDF document text
    • https://nirkongrp.com/ckfinder/userfiles/files/mavuv.pdfIn PDF document text
    • http://nbmounts.com/userfiles/file/1631855830.pdfIn PDF document text
    • https://concertwristband.com/resimler/files/25513281566.pdfIn PDF document text
    • http://www.slappedtogether.com/editoruploadfiles/file/11163262450.pdfIn PDF document text
    • http://qiuyutv.com/userfiles/files/20210911052332.pdfIn PDF document text
    • http://studiopassarotti.it/userfiles/files/41267601623.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec2159cd0f---25399249568.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408f3559c9a---wufakufululesuxusogelubu.pdfIn PDF document text
    • https://agregadoschucuri.sinecsas.com/ckfinder/userfiles/files/26485480527.pdfIn PDF document text
    • https://tunguoilon.tunhua.vn/ipp/images/uploads/files/fanetetukagipifolitoro.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/83879073554.pdfIn PDF document text
    • https://himalayanespresso.com/espresso_ckfinder/userfiles/files/vodimopilexuwo.pdfIn PDF document text
    • http://qianxi.cn/filespath/files/20210901234824.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ee1b74288b---24623420788.pdfIn PDF document text
    • http://robfredo.com/userfiles/file/75403204675.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=yugioh+tag+force+apkPDF 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_off0000b905.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB905 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d11c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD11C 10616 bytes
SHA-256: 2c97a7af974216176213ebb4bebb27e9346a985ac2cafdfb33b145937459e779
font_02_sfnt_off0000e98e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE98E 16588 bytes
SHA-256: 6b65f67cf89dd31fe11d8919b5f44437f48dab667a3846125a67a7dffe461a02