Malicious PDF — malware analysis report

Static analysis result for SHA-256 84314d7acb13f2d9…

MALICIOUS

PDF

86.6 KB Created: 2021-07-13 11:41:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 4666306d5ed423ff43ac4c06f4be1a6a SHA-1: 81b6b8885480b226ad369ead163864c3e1db93de SHA-256: 84314d7acb13f2d90773e181db5d6e126b0473afa4be775b90b2cf3c770fe485
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of numerous external URIs, including links to compromised CMS uploads and disposable hosting, suggests a link farm designed to redirect users. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://crysiq.ru/uplcv?utm_term=angels+at+the+birth+of+jesus PDF link annotation
    • https://zhbiotech.com/CKEdit/upload/files/bekadofom.pdfIn PDF document text
    • http://goref.ru/files/file/22363760954.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/xuzaxofuvakotato.pdfIn PDF document text
    • http://eko-inwest.eu/upload/file/vawidalutupododib.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608da1ef3cc21---bojakewojaxumaxato.pdfIn PDF document text
    • http://tsg-vaganovskoe.ru/ckfinder/userfiles/files/528311514.pdfIn PDF document text
    • http://americanewbie.com/userfiles/file/99526213238.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e5dbe336cf---6276161313.pdfIn PDF document text
    • http://zkojicin.cz/userfiles/file/82985926148.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a531707c21---34975388941.pdfIn PDF document text
    • http://c2r-auto.com/uploadfiles/file/2021070120311673499.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b1891096dbc---50191028138.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/190be4b280ede31632e88498a2b95f82/doguperepasenemalag.pdfIn PDF document text
    • http://sola-brothers.com/userfiles/file/48114918023.pdfIn PDF document text
    • https://actor-conseil.com/files/file/zefogukukativonisojijenib.pdfIn PDF document text
    • https://unosms.us/userfiles/file/31191099601.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/wazadonabuwujitizisedup.pdfIn PDF document text
    • http://whatdwellswithin.com/file/43296559096.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c322cf7574b---68117715422.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/0c230e56f468be14a5a486a47f25a25a/17061343337.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_off0000edbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDBF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000105d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105D1 17656 bytes
SHA-256: 6278ad21e3461883fb1011d8bc4da3cfcb60b774875720c96a95a4f2cbc06d22
font_02_sfnt_off0001342a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1342A 10844 bytes
SHA-256: c7b874917e1440635de39eb8aa10ec875f252ba83fd5984c2d28b0f70a9b7368