Malicious PDF — malware analysis report

Static analysis result for SHA-256 f55a837e958f0b86…

MALICIOUS

PDF

68.2 KB Created: 2021-09-24 15:07:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 60452b6f8488316fb79504c9ed5f0e1f SHA-1: 34e1b111eab02d256da0189f51cc253f38c908f6 SHA-256: f55a837e958f0b86daab7cd87fdd5e906d93d32728c070184b48fba9264b6386
126 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous external URIs pointing to other PDF files hosted on various domains. The presence of multiple unknown reputation URLs suggests a distribution or phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://osingenieria.com/images/admin/file/30606132922.pdf In PDF document text
    • http://laureysnv.be/uploads/files/74774061204.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16137345fbb0a9---sadetap.pdfIn PDF document text
    • https://kcharp.com/ckfinder/userfiles/files/16864870844.pdfIn PDF document text
    • https://casabresciani.it/uploads/file/50008916250.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/b4153bgouhtn0gtrgfvjc7gkn6/zuzovugaponup.pdfIn PDF document text
    • http://lotusburbank.com/uploads/files/joxepapaxuxejukawukidek.pdfIn PDF document text
    • http://vector-mebel.ru/uploads/files/41098215989.pdfIn PDF document text
    • http://f-kcc.jp/user_data/userfiles/files/16351360081.pdfIn PDF document text
    • http://happyhanool.com/ckupload/files/kabujalakeze.pdfIn PDF document text
    • https://vico-real-estate.com/ckfinder/userfiles/files/lizamiwujabev.pdfIn PDF document text
    • http://xinxinhouseware.com/uploadfile/files/diverukovimimetalazawox.pdfIn PDF document text
    • http://hkacca.com/userfiles/84142205400.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/89269947618.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/47185562352.pdfIn PDF document text
    • http://jl-vacuum.com/upload/files/86406020648.pdfIn PDF document text
    • https://heart-calligraphy.com/uploads/files/202109021855326279.pdfIn PDF document text
    • https://pointwebhost.com/calisma2/files/uploads/wemagofiwuwotijud.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210919_53670B38472E9302.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/letokazapobojoxavebul.pdfIn PDF document text
    • http://ivelinabozilova.com/userfiles/file/muwejokawupinikepigixi.pdfIn PDF document text
    • http://mhinflatable.com/upload/file/nifatanulogop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=play+gta+3PDF link annotation
    • https://rt9.rspo.org/ckfinder/userfiles/files/gesalibejebawup.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_off0000b06a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB06A 9852 bytes
SHA-256: e835580d66d1c3b9cd755743e711ea783a7051c311720fd754fee0a56d36065b
font_01_sfnt_off0000c63a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC63A 14684 bytes
SHA-256: 756c97dac3892fbc562397bf84c35e36ac95ef4035129795fb05614372f13539
font_02_sfnt_off0000eb38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB38 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1