Malicious PDF — malware analysis report

Static analysis result for SHA-256 835b4fd0bfca8e45…

MALICIOUS

PDF

79.3 KB Created: 2021-09-08 06:15:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 017b243e594900afd38b4565221d1124 SHA-1: b348679b6d29eb2ad24c8ac1006e4469baaa8051 SHA-256: 835b4fd0bfca8e45e2ec22380ae9382bfc4c1fcf33437fd7094bd61e55f1783f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a malicious PDF, detected by ML classifiers and ClamAV, that contains a link farm pointing to compromised WordPress upload storage. The document body is heavily obfuscated and unreadable, but the presence of numerous links to potentially malicious PDFs suggests a phishing or malware distribution scheme. The primary attack pattern involves tricking users into clicking links that lead to further malicious content, likely exploiting the 'sasol bursary application form 2020 pdf download' lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/79bde3386a978a4067b8a06b7d699c10/79141877519.pdf
    • http://liccuza.ro/stiri_files/file/70993946750.pdf
    • http://akkoryazilim.com/userfiles/file/99928179337.pdf
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/6b9c22b0f3e02105828d04ecb2a3f2a4/navokufofulebogurezikuwim.pdf
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/f816b27fd5e866c6b049c8871ecbb0f5/mefupopisidupabamevopiwe.pdf
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab77b56caa8---45410538731.pdf
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/3q4upo0i7q90su1j4svj07h992/12253272032.pdf
    • http://altelaw.com/uploads/image/file/39230080441.pdf
    • http://infinity-pro.ru/userfiles/file/87671356059.pdf
    • http://gdlejia.com/uploadfile/files/20210810_014126.pdf
    • https://siam-royal-view.ru/data/files/70371174962.pdf
    • http://renovator.cz/files/file/kugaxuziru.pdf
    • http://slstudio.it/userfiles/files/9360900110.pdf
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/e28b6ab1f3cdf243db015a0b5ecde8d6/55020684813.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/94513196917.pdf
    • http://phelieuviethung.vn/upload/files/48464009601.pdf
    • http://artikos.pl/userfiles/file/donufupipa.pdf
    • http://bergepkolcsonzo.hu/userfiles/file/mutegolobezaletisonegezo.pdf
    • http://mhspartan79.com/clients/9/97/97d0d0788ec4d6723ba7be3cd58769e3/File/kunasunoxetomug.pdf
    • https://himalmanpower.com/ckfinder/userfiles/files/4277858415.pdf
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/dovin.pdf
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/0a786b134dbe26b8dc93b6496be0b19b/24671311218.pdf
    • http://videofilm-tv.ru/content/File/mabof.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=sasol+bursary+application+form+2020+pdf+download
    • 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_off0000d094.bin
c3759c5382d65791e487815386c3fa3004e76d5122ce066006a3b0e8db978e16
pdf-font-stream PDF embedded font (sfnt) at offset 0xD094 17524 bytes
font_01_sfnt_off0000fcd0.bin
648e98acfe7329881384bb3f702db87c4e7b6523168836d6f786da6859e7518d
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCD0 11408 bytes
font_02_sfnt_off00011792.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11792 16792 bytes