Malicious PDF — malware analysis report

Static analysis result for SHA-256 b664fbfb3c672bca…

MALICIOUS

PDF

94.0 KB Created: 2021-09-18 16:46:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 68f1d7d56fa84c595284ea21f0c1b4ba SHA-1: 031ccf5347b01e4bcfe403fd4088db5fe1e48caf SHA-256: b664fbfb3c672bcaa231a6af24943691d7c20582d0a4a18f31917b6764d45aa3
126 Risk Score

Malware Insights

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

The sample was detected as a malicious PDF by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to disposable domains and are structured as link farms, suggesting a phishing or malware distribution scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a deliberate attempt to obscure the true destination. While no scripts were explicitly extracted, the nature of the embedded URLs and the PDF structure strongly suggest an attempt to exploit vulnerabilities or trick users into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://4998horo.gmmwireless.com/contents/files/lepisafedibozaxalim.pdf In PDF document text
    • http://massiimo.com/piceditor/file/giravutiranotur.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/091436089019.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/o4cdf75bl2joujnja8k4pc33af/58663266810.pdfIn PDF document text
    • http://primebrokeragetx.com/ckfinder/userfiles/files/11885861852.pdfIn PDF document text
    • https://hotelindigha.com/FCKeditor/file/waxidetubodomi.pdfIn PDF document text
    • https://alteanetworks.fr/img/file/wugumomizafizixunuxag.pdfIn PDF document text
    • http://antasboru.com/guvennet/resimlerfiles/naperojoremekix.pdfIn PDF document text
    • http://lamgi.pl/ckfinder/userfiles/files/75649288568.pdfIn PDF document text
    • http://fantasymusic.it/userfiles/files/40233711561.pdfIn PDF document text
    • http://cjmfgx.morefriendship.com/upload/files/gibogadururutozuloxojeje.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/161407a8e2a52b---66645545170.pdfIn PDF document text
    • https://rubyyadav.com/nbloom/fckuploads/file/nuketugidelojezo.pdfIn PDF document text
    • http://skkouty.cz/ckfinder/userfiles/files/18345759740.pdfIn PDF document text
    • https://thic.muki001.com/plugin/ce1/ckfinder/userfiles/files/6023412607.pdfIn PDF document text
    • http://shannonlakeestates.org/fck_images/file/fenug.pdfIn PDF document text
    • http://residencecarlofelice.com/userfiles/files/lofibobigaxarujilexiwubu.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/files/fuvaguvi.pdfIn PDF document text
    • http://gowowdeli.com/uploads/files/4131386762.pdfIn PDF document text
    • http://maximaviajes.com/FCKfiles/file/93312296435.pdfIn PDF document text
    • http://www.kymenhome-etsinta.net/tiedostot/files/27781648567.pdfIn PDF document text
    • http://balone.net/_upload/file///minifuxobik.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/37843690381.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=kimetsu+no+yaiba+infinity+train+full+movie+onlinePDF 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_off0001070f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1070F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011f26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F26 10788 bytes
SHA-256: dd96c564c8d6571b628504edcc7d71f28ba9f8ab47a6afd26d2f5ac4349dbb12
font_02_sfnt_off0001380e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1380E 19108 bytes
SHA-256: a371afe841102e6284d86f2cc455ac6e01ce75207be82f7ca98cbc4339cf18a3