Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fb3c43065d1be0e…

MALICIOUS

PDF

82.6 KB Created: 2021-08-18 16:58:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 3b8b1731c553cc34e8f4277f2b3ea54a SHA-1: f6c46fd0d232477b9a42b80eb9380541e6407c1b SHA-256: 5fb3c43065d1be0e0c61c971f9fc4aaa28d11e76d2b78e7bb4c1250eda6684b6
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The presence of external URI heuristics and the link farm nature of the document support the classification as a potential spearphishing attachment.

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://eletmodguru.hu/files/files/15841335706.pdf In PDF document text
    • http://vstarmp.cn/upload/files/20210721_063804.pdfIn PDF document text
    • http://www.irrv.org/uploads/files/99059744072.pdfIn PDF document text
    • http://simonkuehner.de/gfx/userfiles/files/72384913728.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/91596305248.pdfIn PDF document text
    • http://dmhu.eu/uploads/uplib/file/wupanire.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-6-21/20210621095249302319.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf6cf024be---72275638997.pdfIn PDF document text
    • http://rockycheng.com/ckfinder/userfiles/files/wuzulomofibepenumam.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bea7b87fcd---valaze.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/pf7mqdf4asceleuioutug0msg0/8548437308.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/3937a6df8ce2ab2f579aa6b92575e3ea/lakexevovoxi.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/7149d3a9c841525e426b879a469d8928/pewila.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090bdba61023---99501391073.pdfIn PDF document text
    • http://dlikefulproductions.com/clients/875850/File/77496395236.pdfIn PDF document text
    • http://abc-tel.ru/data/File/pakokab.pdfIn PDF document text
    • http://zoltysnieg.pl/pliki_wyswig/files/dopetezaromelamoganis.pdfIn PDF document text
    • https://helicopterleasingservices.com/userfiles/files/5290996670.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/2e7b316516556aa9b63ccdf012f93cc1/60243807715.pdfIn PDF document text
    • http://doudou.tw/userfiles/files/bijabasejoropuwun.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b3e361c33aa---95324881627.pdfIn PDF document text
    • https://madame-tina.com/ckfinder/userfiles/files/pudozetopiwasanazilurux.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/b1a3c9e2e5229b4c413f8bd8df10f482/darupavaxubetune.pdfIn PDF document text
    • http://csc0516.com/userfiles/file/20210802165013_k7jcu7.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=medication+calculations+practice+questionsPDF 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_off0000e144.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE144 16088 bytes
SHA-256: 3048a760e3a490a370ca835a9bde51a59895306811d9aff68b2a3e900565afc5
font_01_sfnt_off00010ab3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122CA 10744 bytes
SHA-256: e116edc8ef7a10ef35f813b7e3accbf6804f3b7b511f645766a4ed51fa49d4be