Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f7f3ac34b44837d…

MALICIOUS

PDF

77.3 KB Created: 2021-09-19 04:01:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9e1d0a2f96d23ee03cdfc9a22c3f45d2 SHA-1: 2f0f66cd0dff64f0b6e8272b5697d8d5486a2843 SHA-256: 3f7f3ac34b44837d6ff5e385496aec6f901cfa2a743f0ecb0f9e4f8082ad1350
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to lure users to potentially malicious destinations. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the URL patterns and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://oniceh.ru/uplcv?utm_term=the+most+popular+react+ui+framework
    • http://jakpaisanestate.com/images/upload/files/vobevamaremi.pdf
    • http://smolninskayahotel.com/userfiles/file/45723206826.pdf
    • http://starinviter.com/ckimagefiles/sidifijokekoraxudij.pdf
    • http://asia-test.informacittadino.net/media/files/jitukuwejujolaxegowoxode.pdf
    • http://techsystem.gr/data/uploads/ckeditor/files/lesiwarunitomixolavefoton.pdf
    • http://w-f-l.de/user_img/file/63005476710.pdf
    • https://rafautama.com/uploads/file/gudufisipuzi.pdf
    • http://wmsone.com/eimages/file/potegejosubik.pdf
    • http://studioschicchi.eu/userfiles/files/55589472224.pdf
    • https://nayyaralidada.net/alpha/ckfinder/userfiles/files/weguxobirufiba.pdf
    • http://ukicda.com/admin/fckeditor_upfiles/file/2021091813081880554.pdf
    • https://begili.com/uploads/image/files/3467537387.pdf
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/7nk5m29q0jdi9e4lar92mkgo8b/fibenimovejixu.pdf
    • https://debo-fit.be/userfiles/file///refalakitebovibofafek.pdf
    • https://izometal.net/mm/file/96929249998.pdf
    • https://ixiu-23.com/uploads/files/202109060153167142.pdf
    • http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/runawofuz.pdf
    • https://acconpriti.com/ckfinder/userfiles/files/86550213292.pdf
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/16133cf56ec00d---55699172304.pdf
    • https://tomaszbizon.tomaszbizon.pl/web/uploads/files/93618185634.pdf
    • http://hunicorn.hu/userfiles/file/16709231152.pdf
    • https://vasutaszeneiskola.hu/ckfinder/userfiles/files/50292178845.pdf
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/d9a2f9164f0753f019727bffdd989546/sifipulefoxepo.pdf
    • http://keyflounge.nl/userfiles/file/13092379275.pdf
    • 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_off0000c8bd.bin
49719a66e3cb3e46e0e47bbb703c5e2b806935f5f7d8e5c1dd558724ae2eeb7e
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8BD 10880 bytes
font_01_sfnt_off0000e201.bin
cd0de8963dd6f57e354d7803f7ece14bba1df35ed97e87c473f7b26ec5712d95
pdf-font-stream PDF embedded font (sfnt) at offset 0xE201 17296 bytes
font_02_sfnt_off00010f43.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F43 16792 bytes