Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b1c313e1fb6160f…

MALICIOUS

PDF

78.1 KB Created: 2021-08-31 06:29:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2fb81b91b96f48767cbb98d3917c6142 SHA-1: dc67a6d885edfb097fba17e0319f1e4f510f9911 SHA-256: 1b1c313e1fb6160fc03192cd9e7686205ea6ef3b1bf442030e0af65560b0de2c
156 Risk Score

Malware Insights

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

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these links indicates an attempt to leverage external compromised infrastructure for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609b26288b15e---womisepe.pdf
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/160b05d30857f3---74231924567.pdf
    • http://beymersan.org/upload/files/nezixigujib.pdf
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a98ae70e558---19367877792.pdf
    • http://qianxish.com/ckfind_image/files/numaviferiz.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/3155d3dabd3c20a5d08364945d7f550d/94245821113.pdf
    • https://nezrenpin.com/calisma2/files/uploads/muxorugisojimeporebujov.pdf
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/dcc95ea79116915d82605a0d98648b30/ditowujeduzavekezifugigod.pdf
    • http://shinies.ru/img/lib/file/wadulutananudimezeni.pdf
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160743b5f32c0d---16963123292.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e6a14e7b9c---nonisaverumekoruderaxomaj.pdf
    • http://c-six.it/userfiles/files/buturujolupolenutivaj.pdf
    • https://flvirginia.com/wp-content/plugins/super-forms/uploads/php/files/318132d2edeb71eb0fe8d2328a0ab267/pudukuzumoz.pdf
    • https://doluhosting.com/calisma2/files/uploads/40158068388.pdf
    • http://incomsistema.ru/ckfinder/userfiles/files/18399002073.pdf
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/1f8cb49dfb480ef9e26a1bb78ae2a61a/malupudulan.pdf
    • http://mmbc.cz/_data/user_files/file/72751495291.pdf
    • http://erdbau-rauch.at/49002496970.pdf
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f04b2e8ed4c---foxozunanifo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=one+hour+slippers+crochet+pattern
    • 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_off0000ce0e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE0E 16792 bytes
font_01_sfnt_off0000e620.bin
310b5ee8239c26e99d86d5e0c552e755db55dc9c93f1c7c7b4935cd68733d9f8
pdf-font-stream PDF embedded font (sfnt) at offset 0xE620 17252 bytes
font_02_sfnt_off00011290.bin
af9c77e80872e353f2078d0433b42dc2e30515288e6c9eb13e5b618d3d541976
pdf-font-stream PDF embedded font (sfnt) at offset 0x11290 10596 bytes