Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef99fd9872375b9d…

MALICIOUS

PDF

83.5 KB Created: 2021-09-05 09:13:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: e6993cf0a779f5b240b9f0c8e124d513 SHA-1: e419f5d2a9a2f739c3d0f2078212fd8efd2cb89a SHA-256: ef99fd9872375b9d473bc33ee5ede35e8c3a26b206b460051599d5754f780f2d
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other disposable hosting, likely to redirect users to malicious content or exploit kits. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://takarasushimn.com/userfiles/files/31971096617.pdf In PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/sib9hqmoiptd0v9ubrkf3uhu87/kaxorokofogunaritot.pdfIn PDF document text
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/0bade8802a71abd00ef688416fa9a58c/witesobesi.pdfIn PDF document text
    • http://postelezmasivu-brno.com/ckfinder/userfiles/files/56519758120.pdfIn PDF document text
    • http://skupka54.ru/upload/m/55292034764.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071de6c60c55---zanamifujokufumuvokunazo.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/49251696396.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab2a1e17888---92243150867.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210803104256634.pdfIn PDF document text
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/cf0cf37938c5308130ab93999e5f952c/monukujufirolirigovemonor.pdfIn PDF document text
    • https://wolfgang-photography.com/userfiles/files/45159806256.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/798cce58ebd90f24720fae9bc44075bd/sigobuxijitifozinagabuvim.pdfIn PDF document text
    • http://sushinamu.com/uploads/files/11864946712.pdfIn PDF document text
    • http://dafangtour.com/fckeditor/userimages/file/41384530411.pdfIn PDF document text
    • https://bibliothequedesarts.ch/ckfinder/userfiles/files/67601094863.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079222053e3f---49014920876.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/4trbj7nfbhuq5bupfn0srgfbg5/50416320101.pdfIn PDF document text
    • http://xn----8sbfeahwarn6ac1adp3fb2p.xn--p1ai/userfiles/file/likinuvelozawefimofibe.pdfIn PDF document text
    • http://cba60.com/clients/6/6c/6c2dd71b6188bc8e8f5adc6209c6f86c/File/wofanesugutib.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/50360533960.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9c3f88131---47590014768.pdfIn PDF document text
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/82a59d822c629c81f7532b077c048a08/zugugib.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/nevuboxitakuf.pdfIn PDF document text
    • http://aligokdemir.com/resimler/files/renoworajigezeb.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=fetal+development+pdfPDF link annotation
    • 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_off0000e3f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0D 10344 bytes
SHA-256: 6a2dcb6813f27dda606606e23399e15328e35fad5a2d66d9c9c7e2c5e21fe1a0
font_02_sfnt_off00011358.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11358 17352 bytes
SHA-256: 4a3905773654d71e3c8a26d3b1d8fa1e450a13466a1fc94d2fd3ac2f13f7dcc1

Open this report in the interactive analyzer, or submit your own file for analysis.