Malicious PDF — malware analysis report

Static analysis result for SHA-256 55e8136e82c88a6e…

MALICIOUS

PDF

82.6 KB Created: 2021-09-18 01:17:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: b1587f3d0c38836549709006c6fbc796 SHA-1: 6cff66b435748c898725b7310ae32c4d8fbc351f SHA-256: 55e8136e82c88a6e30c596b43998741418599b319ce6097b821b90e86921827a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://40parables.com/wp-content/plugins/super-forms/uploads/php/files/c3c5a2bee66087597c568a1702487744/22316200758.pdf In PDF document text
    • http://vector-mebel.ru/uploads/files/3568129477.pdfIn PDF document text
    • http://whuntex.ru/userfiles/file/67381417712.pdfIn PDF document text
    • http://lasermedia.cn/userfiles/file/vuwefolixemewubes.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/gasevujux.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/xelavudilikofidunugizazom.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/5ba22d0c12a48833f1d0e41b61b5ca37/28638291613.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/tefeza.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/a31b9b99b11d8ddbaf2e483d1ee05b65/losume.pdfIn PDF document text
    • http://barsugo.com/ckfinder/userfiles/files/99681749995.pdfIn PDF document text
    • https://malabarmail.com/ckfinder/userfiles/files/19254391247.pdfIn PDF document text
    • https://marblo.com/app/webroot/img/files/56743686070.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/c7dfb442969aa1130c1016c3ed60b760/telalakefawefux.pdfIn PDF document text
    • http://33podarka.ru/pictures/files/38968786308.pdfIn PDF document text
    • http://nyitotthetvege.kastelyszallodak.hu/userfiles/files/jopejusapemo.pdfIn PDF document text
    • https://fluffy-chins.com/images/file/8078271067.pdfIn PDF document text
    • http://pillshop.ru/uimg/files/25412656947.pdfIn PDF document text
    • http://dytac.hk/userfiles/buwimaravaviwugeginorep.pdfIn PDF document text
    • http://www.psoevalledeabdalajis.es/ckfinder/userfiles/files/81736904753.pdfIn PDF document text
    • http://xn----8sbemnkjd7bfu.xn--p1ai/design/img/upload/file/budupe.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/c8f38df0724be801d635f95f4312c40f/38854695832.pdfIn PDF document text
    • http://wx-test.com/upload/ckimg/files/202109180318007764.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=upgrade+32+bit+to+64+bit+windows+7+ultimatePDF 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_off0000dc39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC39 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f44b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF44B 17420 bytes
SHA-256: c452580b35792d2c923d9203637351f64e03d46ebd0b780695805558c839e1a0
font_02_sfnt_off0001215e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1215E 11656 bytes
SHA-256: f02bfa206f4feebc764b3122d510f5ea29134ef2db639d98517d215c83f0202e