Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8557ddaac3435de…

MALICIOUS

PDF

85.9 KB Created: 2021-08-03 11:06:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5ff9f1583a8d1b52a2fed7984f41a950 SHA-1: 3e3589be9cdcb55074fb3c4cb00ca13bed92d867 SHA-256: b8557ddaac3435defa0f1b39d7d03cf86a2552e50fd53dc38d25380e8de8cf72
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The file contains a link farm pointing to numerous domains, many of which appear to be compromised WordPress sites used for hosting malicious PDFs. The primary purpose seems to be directing users to potentially harmful content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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=theoretical+and+conceptual+framework+in+nursing+research+ppt PDF link annotation
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/sutisadi7ef81dn059ks3k5pr4/pubesozunekojosaretaz.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/fewej.pdfIn PDF document text
    • https://bawaniint.com/ckfinder/userfiles/files/60909497626.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/c78d126eb6f20eaeebe281998e4623dd/seduduxovi.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16080a56b61181---tametegilidobuveneliviwi.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/nazuguzadinidelizigijugoj.pdfIn PDF document text
    • http://cnzhongkui.com/fckeditor/editor/filemanager/connectors/php/uploads/file/161847519799.pdfIn PDF document text
    • http://actybrain-consult.com/Upload/files/39861626685.pdfIn PDF document text
    • http://angelcabrera.com/FCKfiles/file/vimafupojir.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/27471198726.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b0352b203e2---35575735611.pdfIn PDF document text
    • http://lnimeina.it/userfiles/files/gigixoje.pdfIn PDF document text
    • https://silverstonedevelopments.com/ckfinder/userfiles/files/46158218661.pdfIn PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/lnk8k0r13jr8knev83h16t6m66/95810884415.pdfIn PDF document text
    • http://axiomestates.com/userfiles/file/91995098290.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/bovaporemelupigeroxapiwa.pdfIn PDF document text
    • http://phanphoiongnhuahoasen.vn/upload/files/luxanim.pdfIn PDF document text
    • http://onlineexpert.in/userfiles/file/88385689942.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021061700552973499.pdfIn PDF document text
    • 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_off0000ebc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBC9 11308 bytes
SHA-256: b9311f1c740fe48cf5347e92beba3b416dd34ed91a6a70645d5192662ef55fcd
font_01_sfnt_off0001060c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1060C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E1E 16776 bytes
SHA-256: d3878665fcebed0441fea53cee782b4c4cb9ed1fcd8de1ea1235aeebf9c9060d