Malicious PDF — malware analysis report

Static analysis result for SHA-256 4012170c8aa73969…

MALICIOUS

PDF

81.9 KB Created: 2021-06-13 22:08:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: c2fc07fdbe9df5954021c6434fbfef75 SHA-1: 1f32436cf3e767ab1caa3403279eb8b1c8b47410 SHA-256: 4012170c8aa739695d6e07464f45bc25d6842a9bb0b31ed8df99459cf12c57da
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous links to external websites, many of which are hosted on compromised CMS upload directories. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The document body, though heavily obfuscated, suggests a lure related to 'reading comprehension', which is used to mask the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://coretry.ru/uplcv?utm_term=reading+comprehension+prepositions+of+place PDF link annotation
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcaf77a427e---83687124664.pdfIn PDF document text
    • http://cateringkieuan.com/uploads/userfiles/file/71619572638.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608f14a2c3e2f---99797526977.pdfIn PDF document text
    • http://ixtvs.de/_upload_bilder/_filemanager/file/mozumidiwufokejis.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/fa03efe6828c903e7ed43c68d4ed1b50/71413862366.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160982a6569a6b---41587900871.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/4luckti0rtmubgfj6n4amb19gk/mebewivevijamofofulaf.pdfIn PDF document text
    • http://antwerp-reefer-tournament.be/argt/files/sivoravitadopumovajekebag.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160933ebea082e---bowobipi.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160801577070bf---mosibimovunole.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16078e4b9420c2---54199946690.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/9992b30c5af52ee4cf8c864c5984becf/jopaboda.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn 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_off0000ecec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECEC 5576 bytes
SHA-256: a7558c69c3e60a2cd02b8e1e8616d3b2705017c15e57fe8a43a2950ac0aea224
font_01_sfnt_off0000ffc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC5 10820 bytes
SHA-256: 19ab25906ac3867dbd18ca47fb8fe01fcddd87a0c395cd96295a40fad4d6ba66
font_02_sfnt_off000124ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124FF 16204 bytes
SHA-256: 532315dfdc59b350d447ad91845dd8cc72a836e684f536ab9a4305dc5b53fb8e