Malicious PDF — malware analysis report

Static analysis result for SHA-256 865daf498a0a21b8…

MALICIOUS

PDF

73.9 KB Created: 2021-09-10 20:05:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: a08980a0a3187b13ca81186479dfeba3 SHA-1: e22474e4daf42c0344de93b01d0a4b79ca8726d8 SHA-256: 865daf498a0a21b8eacdf0393f42cfc2690eded8a131eb2c3d90fb07330c0b62
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically identified as a phishing trojan. It contains numerous embedded URLs pointing to a link farm, suggesting a tactic to manipulate search engine results or distribute additional malicious content. The presence of multiple distinct hosts and a high number of links per host indicates a coordinated effort for SEO poisoning or a distribution network.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://belniig.by/public/file/rusububukodufigoroxud.pdf In PDF document text
    • http://portaldo.eu/contenuti/upload/file/gikaxa.pdfIn PDF document text
    • http://dietetyka-24.pl/images/files/gikadoruwotimowigileb.pdfIn PDF document text
    • https://www.bussmann-tiefbau.de/ckfinder/userfiles/files/dadekuliginamukifal.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/38913526273.pdfIn PDF document text
    • http://synphabase.ch/upload/file/29206744824.pdfIn PDF document text
    • https://sayurhijau.com/contents/files/tuguko.pdfIn PDF document text
    • https://kaimano.it/file/36346651676.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/piwozitan.pdfIn PDF document text
    • http://turskazka.ru/ckfinder/userfiles/files/gulonunajonulifomubasu.pdfIn PDF document text
    • http://tplustech.com/images/ckeditor/files/dedobopizuwogevojusax.pdfIn PDF document text
    • http://emploi.nat.tn/ckeditor/ckfinder/userfiles/files/31027861561.pdfIn PDF document text
    • http://vonschickenfremont.com/uploads/files/jizupe.pdfIn PDF document text
    • https://edgecs.com/documents/40559665314.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/80648287384.pdfIn PDF document text
    • http://www.drivingschool-brno.cz/files/files/vekabem.pdfIn PDF document text
    • http://lnshiyue.com/userfiles/file/20210910152852_2075069378.pdfIn PDF document text
    • https://turbooto.vn/upload/files/nubusukenofenekixu.pdfIn PDF document text
    • http://sherwoodchambergolf.org/ckfinder/userfiles/files/48321296290.pdfIn PDF document text
    • https://izyskately.ru/foto/ck/files/77546237407.pdfIn PDF document text
    • http://modaxch.com/userfiles/files/sokumoxaxerexi.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/28528b5324205411fcf8c98cb75a7695/sasif.pdfIn PDF document text
    • http://abwingssuffolk1.com/uploads/files/80998295557.pdfIn PDF document text
    • http://a2hgghk.handylover.com/upload/files/nekodexiparorise.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=demon+slayer+all+episodePDF 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_off0000b94d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB94D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d15f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD15F 18760 bytes
SHA-256: 4c6162c5be5d196c0a5c75222ff92510a5775ba16f0cc431ca76896367515557
font_02_sfnt_off0001026e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1026E 10568 bytes
SHA-256: b5ed764d3776d97ea676e61004136a815215d7338ed947c296ea1b6ee3cbbc7d