Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c661b2dbfa15b08…

MALICIOUS

PDF

81.6 KB Created: 2021-09-06 19:11:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 195a5a27a8fa7f426deaef813c095487 SHA-1: 76c7668218808b53e4cc761534f60938c3e35e6d SHA-256: 3c661b2dbfa15b08e4d92b6777523317afd051c3582de45f47121c22105d1400
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristic firings confirm the malicious nature of the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://files.ibiza-ferien.de/file/59702243181.pdf In PDF document text
    • https://nabijdefossa.nl/upload/files/40641362588.pdfIn PDF document text
    • https://keepingscore.org/userfiles/file/busuvumodigesa.pdfIn PDF document text
    • http://446888.top/userfiles/file/33856661231.pdfIn PDF document text
    • http://spostojow.pl/userfiles/file/figinobulemowufemon.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/amd73q2fpo87f6kbu9semc795u/44286583353.pdfIn PDF document text
    • http://scuolascifondocortinadolomiti.it/userfiles/files/mobujoxeketiritenurovoz.pdfIn PDF document text
    • http://interreg-ipa-husrb.com/downloads/7793175830.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/928etsnsa566mdumb79lch44ll/wipimupu.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/lotubutupejalezajekub.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/1c5540cb733b98d3908f9b4c80456919/33553470089.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/ca9c797b55913de666a1a41029dd39e9/xunuposa.pdfIn PDF document text
    • http://atomleasing.ru/media/File/16683455459.pdfIn PDF document text
    • http://mgbig.com/upload_fck/file/2021-8-31/20210831015858123897.pdfIn PDF document text
    • http://954move.com/clients/4890/File/19867603799.pdfIn PDF document text
    • http://yomamasushitogo.com/uploads/files/49785055866.pdfIn PDF document text
    • https://tripleccompanies.com/wp-content/plugins/super-forms/uploads/php/files/e64d8a5e5a89ffb147ed01639382979b/37968220594.pdfIn PDF document text
    • http://pestcontroluttara.com/ck/upload/files/82614562464.pdfIn PDF document text
    • https://jxlmedu.com/file/files/20210826_214726.pdfIn PDF document text
    • http://eurekaloggers1970.com/clients/a/a4/a4917853023b9a70bc4506ca58f09c65/File/puxufoxufawarasaxugokipu.pdfIn PDF document text
    • http://nfrostov.ru/upload/files/nogakajutelezubizatar.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160df89885a564---75476257943.pdfIn PDF document text
    • http://birzebbugastpetersfc.com/files/file/viwapimixegipan.pdfIn PDF document text
    • http://uralcomservis.ru/crn_fls/crn_files/razanerirovogude.pdfIn PDF document text
    • http://fluitec.fr/ressource/site-image/files/bopotikazikevimap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=family+and+friends+1+test+pdfPDF 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_off0000db49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB49 10680 bytes
SHA-256: 48ddf8e19a121583d86f702db35e26b92a5aaed8c6ab8c3b1c19f880f429ba6f
font_01_sfnt_off0000f3c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C6 17212 bytes
SHA-256: c49f372623e1a563f65531944cc56b86237d0b6089e738eaa9d85a9fc233ef28
font_02_sfnt_off00012079.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12079 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1