Malicious PDF — malware analysis report

Static analysis result for SHA-256 83150ffbc43895ac…

MALICIOUS

PDF

70.7 KB Created: 2021-09-06 03:38:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 16c12d12f0ab73e01aefaee17b90af1c SHA-1: 03971fcb4b92dd77a764f601bf926255ddae10d4 SHA-256: 83150ffbc43895ac9287f07820a1ec60dac3edf264053c371dafa828042c8bc0
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external resources, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the PDF structure and URL heuristics point to a downloader or redirector pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://waterreducer.cn/d/files/gizetilezavat.pdf In PDF document text
    • http://gagutp.com/sa_upload/userfiles/file/20210604122625.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607585e853ca3---58275180545.pdfIn PDF document text
    • http://artistalexanderkanevskyroyalshakespeareglobetheatrelondon.com/clientMedia/file/zususoripajokusi.pdfIn PDF document text
    • http://studiolorenzoni.eu/userfiles/files/dedala.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/di2i228p8931apf6ut6nglrkg1/1097622976.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610a6d433507e---nowubejanifefu.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/d6718c729266ec7e2cbc17ce6c42a4ec/sofaxedu.pdfIn PDF document text
    • http://www.novosib-sport.ru/ckfinder/userfiles/files/jejavesa.pdfIn PDF document text
    • https://agencement-menuiserie-var.fr/stockages/files/wugegimapuwej.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160f9cbcc89488---likunuvotawoberozorapaxe.pdfIn PDF document text
    • http://aven.su/userfiles/file/logeravu.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/2051ef925ed5a74b7947ed9e8f658401/futiwexupupejedozupi.pdfIn PDF document text
    • http://khonggianmang.com/upload/files/94095220117.pdfIn PDF document text
    • http://gilbertthomasreunion.com/clients/5/5f/5f56fe696be94dde62972871c8a9bc28/File/fiwadal.pdfIn PDF document text
    • http://xn--90aoj0agf7cq.xn--p1ai/uploads/files/77446882044.pdfIn PDF document text
    • http://ekolojikweb.net/upld/userfiles/file/30188422529.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f9cbda3daed---74835062659.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/zumom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=math+worksheets+double+digit+additionPDF 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_off0000b4d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ccec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCEC 10936 bytes
SHA-256: e83cdf80a7bd354e4d6c00ff35e8ae45659804e486610c6d4365842d5f7541d5
font_02_sfnt_off0000e60c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE60C 15468 bytes
SHA-256: 396b10526e00ac4f76e423194f24a4569fc4ba14b4a4764bbb02fc8ef9b2d20b