Malicious PDF — malware analysis report

Static analysis result for SHA-256 aac63663a7723d55…

MALICIOUS

PDF

95.1 KB Created: 2021-08-13 10:43:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 58382d69e601af51f5109b9e25621a78 SHA-1: 5baae49c2d4fd24c4e022379115ee657660398f0 SHA-256: aac63663a7723d5533c2fdc64ccb41dcfdbeda3b7526c490cac3a50589d0571b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to a link farm hosted on disposable or compromised domains, suggesting a phishing or malware distribution campaign. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://irlanc.ru/uplcv?utm_term=exam+fm+study+guide+reddit PDF link annotation
    • http://chip-chup.hu/upload/file/nazumorubevenitutuf.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16079bf0783a65---82810337478.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/mdgmr2und1vvbsocev8vi2vt7e/83096575905.pdfIn PDF document text
    • http://shipagents.nl/uploadfiles/file/pefufemezizugaxeberajol.pdfIn PDF document text
    • http://waberry1969.com/clients/877040/File/kezomuz.pdfIn PDF document text
    • http://btfa.tw/upload/files/65755149725.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/rerizexanob.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160b457c569b35---21966069146.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fff493e079---daguwifepobifap.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/qphhkhc0avel7tf3ibj3ul8vk0/80677698390.pdfIn PDF document text
    • https://healthcareadvisorsgroup.com/wp-content/plugins/super-forms/uploads/php/files/hboeeccfa1v4mfrg1seb9c6dj7/54447795753.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/9n2erofpv573kg0gf0mtsbmf2c/52888088164.pdfIn PDF document text
    • https://www.peltonfell.org.uk/ckfinder/userfiles/files/vibibapavazupib.pdfIn PDF document text
    • http://faizleathergloves.com/userfiles/files/rodekujijifalurixuw.pdfIn PDF document text
    • http://gibisch.biz/files/files/xujefodaxevadi.pdfIn PDF document text
    • https://webmenuplus.com/images/file/fipunotedo.pdfIn PDF document text
    • http://toyotarentcar.net/FileData/ckfinder/files/20210808_D90C273760A2985F.pdfIn PDF document text
    • https://comfortinnbarrie.com/phpsites/vertical_living/uploads/file/83808718322.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/2174deab716deaf45b82685926497ff3/77628457728.pdfIn PDF document text
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/070c583cc22fbd1ed59d9ea48ea64ab9/jujisaziruxigupit.pdfIn PDF document text
    • http://mirandatutoringcentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16098456fc1bce---pevujifog.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608d3226961af---potaxeziduko.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_off00010ccc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CCC 10728 bytes
SHA-256: 3bd6e3f366889cd61200b6b3fc0e28c875f2701b7d47c66b68e41f39c568ff78
font_01_sfnt_off00012545.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12545 18608 bytes
SHA-256: a2c9fd0b77a7daeb66281de4d0d7325dd7776ebaf277a45cdfaa2a47c7826c2f
font_02_sfnt_off00015681.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15681 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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