Malicious PDF — malware analysis report

Static analysis result for SHA-256 636385fb99a1df36…

MALICIOUS

PDF

76.6 KB Created: 2021-09-29 01:58:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6562464593544e2f733e00d2cb1dc25d SHA-1: d45167cfe0fa9004b19c6127643616853e32dae2 SHA-256: 636385fb99a1df3668b6c6b31c2ff87cf7d08e8b670d6533c7cbc2ea4f2aad1e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and numerous external links, several of which point to compromised CMS uploads or are part of a link farm. The presence of JavaScript suggests an attempt to execute code within the PDF viewer, likely to download additional payloads or redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://lse.hu/userfiles/file/15583007234.pdf
    • http://patanamachine.com/imgUpload/files/zirasepejafuf.pdf
    • http://wagnerpc.com/userfiles/files/53305841264.pdf
    • https://mayersoffice.com/userfiles/file/sabojofigi.pdf
    • http://ongxoanhdpe.vn/upload/files/94832005207.pdf
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/161397b8b8848d---resezumiketurumoxe.pdf
    • http://provia-events.de/pics/fotos/1/file/lerul.pdf
    • http://musclecar-taps.com/js/upload/files/lomododuzubogaxirafew.pdf
    • http://mtkshop.com/images/uploads/file/18013398769.pdf
    • http://transcash.com/ci/userfiles/files/xiputejekiwumevit.pdf
    • http://closehorses.com/userfiles/file/xebozotevusi.pdf
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/c0lmlahtudaqmgdgjntbrt1548/10821955579.pdf
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/f2c69731ec93afe7e448e304827a77c7/59239188875.pdf
    • http://oumkua.com/userfiles/file/615268181.pdf
    • https://lmetinternationalschool.in/ckeditor/ckfinder/userfiles/files/55803889423.pdf
    • http://zhongyuemedia.com/filespath/files/20210922215426.pdf
    • https://anna-bel.com/app/webroot/files/userfiles/files/42128841617.pdf
    • https://cortopolis.ar/userfiles/file/60450871409.pdf
    • http://1night2day.com/ckupload/files/tasilizogenol.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/r38mq2qqk6ulkpbp19ul05uvaf/92333145701.pdf
    • http://dellalontra.it/userfiles/files/nipawedapa.pdf
    • http://www.deep2001.com/images/library/File/33793291710.pdf
    • http://tropo-design.com/ckfinder/userfiles/files/66821734745.pdf
    • https://nghiepvu.udicmanpower.vn/uploads/news_file/54634515164.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=excel+vba+auf+android+tablet
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000be9d.bin
1560ca72c34c6327d1981052b799b2f03d332aeb297076b905922de376c8ed58
pdf-font-stream PDF embedded font (sfnt) at offset 0xBE9D 10692 bytes
font_01_sfnt_off0000d746.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD746 16792 bytes
font_02_sfnt_off0000ef58.bin
651c4c33254f72b981a1483197ab796f4aa3b80925e181e13e97b7441a640a9f
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF58 19804 bytes