Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c6777b1a8d59f28…

MALICIOUS

PDF

86.1 KB Created: 2021-09-18 09:37:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8b5aeb7697de196e6fc4e76c6e278a08 SHA-1: 6638f597fc2b9a3bfc9a07df45b640a2094d8a8a SHA-256: 1c6777b1a8d59f28d1cd6573bf657132e2537546f42b7e4821e11150b7d1fdae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the nature of the URLs and the PDF structure suggest it's intended to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://coretry.ru/uplcv?utm_term=aurasma+app+for+android
    • http://arcos-eff.it/userfiles/files/90238336918.pdf
    • http://flyingfish-stay.com/userfiles/file/88364989420.pdf
    • http://skene.es/userfiles/file/vepiximixafejawivejal.pdf
    • http://pc580.cn/upload_fck/file/2021-9-3/20210903224825105097.pdf
    • https://lrsdev.com/userfiles/file/94936136372.pdf
    • https://triosms.com/userfiles/file/24839623716.pdf
    • https://www.aukuras.org/ckfinder/userfiles/files/10257596561.pdf
    • https://tresonance.org/uploadfiles/figogixavusodajusowebewa.pdf
    • http://marjoleintje.nl/include/userfiles/bamafizedezuxi.pdf
    • http://seychelles-resort.com/images/blog/file/24939502661.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137ff5dee9e2---kunatakupenapefuselepe.pdf
    • https://polandpools.com/contents/files/85578919249.pdf
    • https://amatnieks.com/pictures/image/5292149020.pdf
    • http://abacusnancy.com/userfiles/file/nasijutabivixapodo.pdf
    • https://polresseluma.com/assets/ckfinder/core/connector/php/uploads/files/67170712826.pdf
    • https://gulceoyunlar.com/calisma2/files/uploads/16852498600.pdf
    • http://varadimasszazs.hu/uploads/files/50734730127.pdf
    • https://martensmgt.com/business_school/uploads/file/jorezavofavejabalugolazov.pdf
    • http://jmlukanich.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/47720717190.pdf
    • http://dcbestwings.com/uploads/files/lanukuv.pdf
    • http://asja.ua/userfiles/file/burufawalazizikekuviviw.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/27d5546e05b8cfaf6932d31193ef33a0/54752880474.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/407d15de6994aa788f5be64d3f337cb9/xuzeri.pdf
    • http://dd-eng.com/files/files/42505880316.pdf
    • http://capesociety.ca/uploads/files/62507022755.pdf
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614219bb48190---67646684478.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_off0000ec00.bin
f0b54830491ddbd314588a4f705fbdf5961bfb775a75da5d524c34f0a3e57788
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC00 10464 bytes
font_01_sfnt_off000103ac.bin
684e7cd9946ea5885d96bacd82dab1307c7f4370b3dea4ce1824916840abdb93
pdf-font-stream PDF embedded font (sfnt) at offset 0x103AC 18056 bytes
font_02_sfnt_off0001328c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1328C 16792 bytes