Malicious PDF — malware analysis report

Static analysis result for SHA-256 16cf81903f66f896…

MALICIOUS

PDF

125.4 KB Created: 2021-07-08 02:50:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 27c06392930e4fc879516e190dd3f3a5 SHA-1: bc1162f4b7004060c339e609ed94539e417a9687 SHA-256: 16cf81903f66f896ad6096073f9dbd39bd68672ab3247b9dddd22b07189b471d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised WordPress upload locations and other disposable hosting sites. The embedded URLs suggest an attempt to distribute malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://africanresearchcenter.com/userfiles/file/baxukumixesotesesurejojo.pdf In PDF document text
    • http://jnafarms.com/clients/864068/File/51219939586.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file///xoxefukedusepemivinunan.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160790f916230a---4524892923.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b420592d314---sirimobitupe.pdfIn PDF document text
    • https://oklogistic.lv/upload/file/sojub.pdfIn PDF document text
    • https://fotofidelity.cz/userfiles/file/dobag.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608db26105350---77584659724.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/2f225302ff4ea14a4ceae4fd74a29778/wikejo.pdfIn PDF document text
    • https://balajihighfields.in/userfiles/file/38548969783.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/a92ed6ca461b07f7ceb525aa345fdbf7/kisati.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c4da65b33f8---71539005301.pdfIn PDF document text
    • https://bechtoldpaving.com/wp-content/plugins/super-forms/uploads/php/files/0036c15c02f253098dc5ce4f08e223c0/dakobebifiti.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16082f16752ab7---50075093814.pdfIn PDF document text
    • http://fairview68.org/clients/c/ca/ca24e3df3ff7fa9b839de6c08aba9959/File/31318022342.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e28c19ea54---67989649106.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c03513b1e53---27537554598.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16094b4fc10f9c---13748341187.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/2021515233303875.pdfIn PDF document text
    • http://vitacanes.com/uploads/files/fuzudozu.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/6216q6i55cttpo6tah86mrupp4/wuwad.pdfIn PDF document text
    • http://airmon.hu/images/files/kekuko.pdfIn PDF document text
    • http://tfwdynasty.com/clients/f/fc/fc55782506b94f933057639757072b2a/File/revawowi.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/cd35be9050ef502da1caa3dbff14d9bb/24426073761.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=ssqq+christmas+puzzle+answersPDF 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_off000187a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x187A3 17832 bytes
SHA-256: e7acab281271dd23c8a448f1890af71464a34a6d47df1f51696e5fcba1cb1ad2
font_01_sfnt_off0001b687.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B687 10984 bytes
SHA-256: c7951c90945c019cfb4b858acf01552b09471c0bd4fcda7d434d660fcaa50f30
font_02_sfnt_off0001cfed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CFED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1