Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac59dca4b7d72d48…

MALICIOUS

PDF

70.9 KB Created: 2021-10-04 08:58:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 4fa06f77a27ad09e779cbec10e4a82eb SHA-1: 1b4cbd18e44a7d5b015a9fcd6273fffedd0744f0 SHA-256: ac59dca4b7d72d4833db9d9eec15128073821326f49eaf5cb4bfb787cbe2cb0c
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, with numerous embedded URLs pointing to potentially malicious or disposable domains. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose, which is likely to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://saconsultancy.com/userfiles/file/44889246452.pdf In PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/3a52b8a1897680f91c525abc05d3eae5/75335957963.pdfIn PDF document text
    • http://grubstreet.ca/ckfinder/userfiles/files/42235990697.pdfIn PDF document text
    • https://stka.gr/ckfinder/userfiles/files/21484320728.pdfIn PDF document text
    • http://sjanzee.nl/file/xekamoju.pdfIn PDF document text
    • http://thumpamonpally.com/userfiles/file/70561715519.pdfIn PDF document text
    • http://arhive.np-sp.ru/img/file/50303760532.pdfIn PDF document text
    • https://birudongker.com/contents/files/gosumanopitaxogudi.pdfIn PDF document text
    • http://vetportonaccio.it/userfiles/files/52930420749.pdfIn PDF document text
    • https://gestcargo.com/uploadfiles/file/89001080026.pdfIn PDF document text
    • http://phulieumaymacbaoco.com/hinhanh_fckeditor/file/xikimipibozamewibusafaja.pdfIn PDF document text
    • http://studiopol.com/userfiles/files/mogexamixuvut.pdfIn PDF document text
    • https://stgeorgedentalcare.in/ckfinder/userfiles/files/81532379082.pdfIn PDF document text
    • https://expobar.vn/app/webroot/files/images/pages/files/29315629992.pdfIn PDF document text
    • https://workinhotel.com/upload/fckfile/debiwirukirovige.pdfIn PDF document text
    • http://jszl-rolls.com/filespath/files/20211002160429.pdfIn PDF document text
    • http://liily.jp/upload/file/20210925172824.pdfIn PDF document text
    • https://gifarlcm.com/upfiles/editor/files/47978706844.pdfIn PDF document text
    • http://xn--b1agpbmdtf.xn--p1ai/upload/file/vetewiliparubis.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146850111332---95312227412.pdfIn PDF document text
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/25967217787.pdfIn PDF document text
    • http://signauction.net/userfiles/file/88138694774.pdfIn PDF document text
    • http://tech-sub.com/userfiles/file/nopikadofepoxupak.pdfIn PDF document text
    • http://perchegouet.com/ckfinder/userfiles/files/dizasetuzabatev.pdfIn PDF document text
    • http://donghozibistore.com/luutru/files/8174311998.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=to+whom+it+can+concernPDF 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_off0000b302.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB302 10332 bytes
SHA-256: 7fd7c196cd6ef34961243eb5e5b6209feb6b513555cafb336385fe16e1ce3ca8
font_01_sfnt_off0000ca2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA2E 17516 bytes
SHA-256: d080a93235411082136dfaea38c52ac009be19fb110b587ff83548e1bc8bf8b4
font_02_sfnt_off0000f664.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF664 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1