Malicious PDF — malware analysis report

Static analysis result for SHA-256 2a99fa00fe9eec43…

MALICIOUS

PDF

87.1 KB Created: 2021-09-22 09:23:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4134e47d855c9f05f495da470d929eb1 SHA-1: 90460559773413d61978e7e3f0ab380f92bf8653 SHA-256: 2a99fa00fe9eec4305decf4cbd68f1d16d2d8e14e480677ac698cd13e88842c3
156 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm or redirection scheme. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://brickchamber.com/ckfinder/userfiles/files/3000550694.pdf
    • https://www.baust.edu.bd/app/webroot/ckfinder/userfiles/files/14904411914.pdf
    • https://bimstudioinc.com/media/files/tavapofinedomasu.pdf
    • https://dubaimotorcycletours.com/uploaded_images/files/misugev.pdf
    • https://munis-roquesalbes.cat/demo/vilalba/imatges/file/bikaletiserupojuwazaweg.pdf
    • http://myphamasia.net/upload/files/wijonotojanatonod.pdf
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/161348418db5e4---fukuronakujenatokabo.pdf
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/696dd75b8473c81a28b7c48ed1f58a21/vereta.pdf
    • http://crimesla.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/14051673152.pdf
    • http://live-net.it/file/busenasusis.pdf
    • http://www.gyndoktors.de/ckfinder/userfiles/files/ronarupowoluwowojazutoxas.pdf
    • https://photopoligrafic.ru/ckfinder/userfiles/files/dekezorowixaposimon.pdf
    • http://ceramvetro.net/userfiles/file/9517540490.pdf
    • http://draftingfloorplan.com/ckfinder/userfiles/files/6291537244.pdf
    • https://sanagustin.cl/files/4259915490.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135c8504056c---20688470116.pdf
    • http://onfireinteriors.com/userfiles/20977375570.pdf
    • http://the100voicesofgospel.ch/fichiers/newsletter/file/tanodezejilam.pdf
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/161375c09b2a2c---8612077521.pdf
    • http://unitez.net/images/newtech/files/kuwepamu.pdf
    • http://asesoriazabalburu.org/azaba/files/file/78893761547.pdf
    • https://www.adoz.cz/ckfinder/userfiles/files/23488519737.pdf
    • http://chernogolovka.inhome360.ru/admin/ckfinder/userfiles/files/52443201018.pdf
    • http://babijie.com/upload_fck/file/2021-9-18/20210918235847388920.pdf
    • https://homestayhoian.vn/uploads/image/files/pemexetevagalik.pdf
    • http://giaexploring.it/userfiles/files/52785960301.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=can+you+use+android+tablet+as+second+monitor
    • 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_off0000ed5b.bin
1960e30530c2785cce3189643f574ad783949141bf9db5b3519ba102e75250cc
pdf-font-stream PDF embedded font (sfnt) at offset 0xED5B 10916 bytes
font_01_sfnt_off000106af.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x106AF 16792 bytes
font_02_sfnt_off00011ec1.bin
313549ed190c6e75a835ab94b917b732d2129b3a8c9b76352607c42f7e1dcc19
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EC1 18336 bytes