Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa73f4331714a5a5…

MALICIOUS

PDF

72.5 KB Created: 2021-09-27 04:04:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b4242f676d50e702d37577de5b6b06cb SHA-1: dabf859a0955126010c5e99ef2b8ae3fa5d64f5e SHA-256: aa73f4331714a5a50b10a8732562327b1b7970bf83eb134bd2c6ac207a04035a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external links, many pointing to disposable hosting, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to malicious sites for further exploitation. No scripts were extracted, but the PDF structure and heuristics point to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

Heuristics 6

  • 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.
  • 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 https://calendarsunrooms.com/userfiles/files/47691181321.pdf In PDF document text
    • http://najlepsietorty.sk/uploads/fck/file/77655084093.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/ddb2132701eb60e82ffb094ad1f1773a/tepakakavetibiros.pdfIn PDF document text
    • http://vandervalk.reviews/app/webroot/files/userfiles/files/26044426675.pdfIn PDF document text
    • http://bankerz.in/qpic/files/xemozalujurirez.pdfIn PDF document text
    • http://linyuepharm.com/upload/files/86246893176.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/99406505406.pdfIn PDF document text
    • https://ww150002.linebot.net/upfile/files/20210908012335.pdfIn PDF document text
    • http://ydyb.com/filespath/files/20210909201843.pdfIn PDF document text
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210919160239.pdfIn PDF document text
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/63558137298.pdfIn PDF document text
    • https://dom4m.de/userfiles/files/fezidiz.pdfIn PDF document text
    • https://bibonatura.com/ckfinder/userfiles/files/47157283263.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/44477210500.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16139318b81ff6---xijasajezorevovikoj.pdfIn PDF document text
    • https://rh4-h1tapi-turbo.com/contents/files/zuwotupadaxapafupef.pdfIn PDF document text
    • http://thementalhealthadvocates.org/files/userfiles/file/99248130144.pdfIn PDF document text
    • https://thehouseproduction.net/file/lokujetubiz.pdfIn PDF document text
    • https://frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/7425436574.pdfIn PDF document text
    • https://hattoco.vn/images/ckeditor/files/9272653084.pdfIn PDF document text
    • http://madurastones.com/userfiles/file/26382812668.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/risogaxabedexepajuz.pdfIn PDF document text
    • http://ellev.fr/upload/files/xegut.pdfIn PDF document text
    • http://dd-eng.com/files/files/42505880316.pdfIn PDF document text
    • https://willmarareachamber.com/ckfinder/userfiles/files/2601493046.pdfIn PDF document text
    • http://1137.jp/app/webroot/js/ckfinder/userfiles/files/74534182477.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=android+phone+unblock+numberPDF 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_off0000b6b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6B6 17460 bytes
SHA-256: c1edd40154d76fbf1250f4f501266bc9d96b1c793a0b4f1518b1fc0ac6a2db66
font_01_sfnt_off0000e442.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE442 10664 bytes
SHA-256: 6357cc5b74ee67053accac8880ca264fe3604f26a8d981391311b2a8826d39bd
font_02_sfnt_off0000fc2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC2D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1