Malicious PDF — malware analysis report

Static analysis result for SHA-256 e35d7680a8169151…

MALICIOUS

PDF

72.1 KB Created: 2021-09-11 00:19:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c7764e0c2e4eef0265a71ff7dba87862 SHA-1: 0c8a6ca2600e21b4b9e16fdf5b7fa8aaf6193c41 SHA-256: e35d7680a8169151417a955ad77fdc04a6077d17a2b7d0dba118b9a94dc5ca45
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external URLs, many pointing to PDF files on unknown domains, suggests a phishing or malware distribution scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a link farm on disposable hosting, likely for obfuscation or evasion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://change4best.ru/upload/file/wifenovagunumumetaro.pdf In PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/161355dac54c77---xutekokusotavevejuzovetur.pdfIn PDF document text
    • https://noble-program.site/js/ckfinder/userfiles/files/34937456407.pdfIn PDF document text
    • https://flomogroup.com/upload/files/tiwopexupejatixowixiv.pdfIn PDF document text
    • https://eirai.org/editor/ckfinder/userfiles/files/78685443162.pdfIn PDF document text
    • http://aurastaffing.es/upload/file/kofoka.pdfIn PDF document text
    • http://tele-klass.ru/i/upload/files/5031544698.pdfIn PDF document text
    • http://mayjack.com/upload/files/42689482388.pdfIn PDF document text
    • http://opusincertum.it/userfiles/files/nalidovaxuridizabagafabi.pdfIn PDF document text
    • https://zaragozadenoche.es/upload/files/xiwodorerorobibitadu.pdfIn PDF document text
    • http://195exim.com/datas/files/jupubuw.pdfIn PDF document text
    • http://oembag.com/uploads/files/202109010727395900.pdfIn PDF document text
    • http://feldbach-tourismus.at/files/32599846882.pdfIn PDF document text
    • http://elosc.com/upFile/file///ITX202109070936086222.pdfIn PDF document text
    • http://hwayinn.com/image/files/20210906_222627.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/84403577830.pdfIn PDF document text
    • http://kerrya.com/ckfinder/userfiles/files/24331523735.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137a1792b9a7---fanokugeworifazin.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16132c30bb03f5---73758915027.pdfIn PDF document text
    • http://konditsionery-zheleznodorozhnyi.ru/upload_picture/file/wegavudolozojatubigawuta.pdfIn PDF document text
    • http://archpiudue.com/userfiles/files/wapiwalinonosir.pdfIn PDF document text
    • https://dlt-nkp.com/fileupload/file/58011294819.pdfIn PDF document text
    • http://ipsaix.com/ckeditor/ckfinder/userfiles/files/46001006129.pdfIn PDF document text
    • http://hijoin.hu/editor_up/zomarawigedemiwi.pdfIn PDF document text
    • http://mitroc.com/userfiles/file/2668657419.pdfIn PDF document text
    • http://jl-vacuum.com/upload/files/17965263759.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=snapchat+copy+and+paste+artPDF 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_off0000b940.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB940 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d152.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD152 16068 bytes
SHA-256: 37698cecdee7489bd3d740bb4307f436bffde2414fd901b97bfeb0ed51e2c493
font_02_sfnt_off0000fa94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA94 10660 bytes
SHA-256: fde0df04dfffd3df01d94b3c1a00d68d22d018a6a9cc9656cd7564850e584e7d