Malicious PDF — malware analysis report

Static analysis result for SHA-256 86abb260a1b4b2ca…

MALICIOUS

PDF

75.1 KB Created: 2021-09-12 10:37:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: f0e2f1340ccb49086ca19dc2697e8299 SHA-1: 5e2caf97adfa1a46b57c396da38e1c8d1ac4b146 SHA-256: 86abb260a1b4b2ca410ea4d1b4f6ce8867c6a79f764d821e223488921b4f9b0a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as a phishing trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting. The document body is heavily obfuscated and unreadable, suggesting it is designed to obscure its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://stellamaris.cz/userfiles/dodoxujidolaje.pdf In PDF document text
    • http://agapetown.net/ckfinder/userfiles/files/43445107906.pdfIn PDF document text
    • http://homeloanz.net/images/e/file/16667037842.pdfIn PDF document text
    • http://oishisushigd.com/uploads/files/47530856983.pdfIn PDF document text
    • http://artpolyclinic.com/file/files/renuminukoruzil.pdfIn PDF document text
    • http://netcentricnj.com/ckfinder/userfiles/files/20680253448.pdfIn PDF document text
    • http://kerama.altrodesign.eu/ckfinder/userfiles/files/bupodulijelov.pdfIn PDF document text
    • http://ceresasrl.it/userfiles/files/56045960165.pdfIn PDF document text
    • http://nilesk.com/userfiles/file/sowowigagitisabodi.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/vlfi3uhb3i11t4sadsl5jscgua/45570172077.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/pevuwaraveladokuguwes.pdfIn PDF document text
    • http://kovospm.cz/fotky/file/85378845466.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/f5b4010ca40b6673307d47c5f77c78ee/povepa.pdfIn PDF document text
    • http://orderbestwings.com/uploads/files/59188967571.pdfIn PDF document text
    • http://hoachathoanggia.com/userfiles/file/90868131154.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/f4df012d0d9530019d2fe5404c41851a/65609792572.pdfIn PDF document text
    • https://simorgh.it/uploads/file/14409563538.pdfIn PDF document text
    • https://artinterior.bg/userfiles/file/41391278205.pdfIn PDF document text
    • https://valubil.com/public/uploads/cms_file/cms_files/72771305191.pdfIn PDF document text
    • http://adamex.ukrkarta.ua/fckeditor/userfiles/file/xinixipez.pdfIn PDF document text
    • https://khotelmarket.com/FileData/ckfinder/files/20210912_EC6F14335A836F13.pdfIn PDF document text
    • http://narnivet.com/userfiles/files/12494051197.pdfIn PDF document text
    • http://rutka.pl/media/upload/files/49da14c08c85b5f6b9259b414e7d2305.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=friv+original+games+listPDF 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_off0000c3bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dbcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCF 16724 bytes
SHA-256: 77c9a43a71f9994252346d4faf50a6e9682fc1606f9517b586cbc50cd7a7eabb
font_02_sfnt_off000106ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106AC 10492 bytes
SHA-256: a76e874e67deb069668f545d89b336b52867dbc2b0392952251580b6825605d6