Malicious PDF — malware analysis report

Static analysis result for SHA-256 81653d891a442666…

MALICIOUS

PDF

87.0 KB Created: 2021-09-20 10:45:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7c5ce3bdda9f474ebe0d35c1224bfab4 SHA-1: 6696930ad3a403b99eb32d5af4d339d6836d8aee SHA-256: 81653d891a442666f42d97718859da8ded50808b5b8402a2d8fc17a145cd7fde
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URLs, many of which are hosted on disposable domains, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards it being used to redirect users to malicious websites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 https://pixomot.ru/uplcv?utm_term=naruto+shippuden+ultimate+ninja+storm+revolution+free+download+for+android PDF link annotation
    • https://altonika.pro/files/fck/file/nifetupuweviner.pdfIn PDF document text
    • http://morecoredesign.com/images/imageUps/files/kaguxiripegibuvi.pdfIn PDF document text
    • http://villa-carlshorst.de/sites/default/files/file/97751751144.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/48541483148.pdfIn PDF document text
    • http://www.saletime.gr/admin/fckfiles/file/wijaforufaromewi.pdfIn PDF document text
    • http://futureinfashion.com/ckfinder/userfiles/files/23459520346.pdfIn PDF document text
    • http://horvathortho.hu/tmp/kifanaxinabesixuzubazore.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/71110007458.pdfIn PDF document text
    • https://suavitinhtannha.net/upload/files/82580848662.pdfIn PDF document text
    • http://macabrey-luthier.fr/data/Files/towiguxafafa.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/99664418157.pdfIn PDF document text
    • http://ahknchem.com/upload/files/74909414931.pdfIn PDF document text
    • http://a-swiss.com/upload/userfiles/file/maziv.pdfIn PDF document text
    • https://ikansambel.com/contents/files/vorevemidowamujufe.pdfIn PDF document text
    • http://gdfsztal.com/uploadfile/files/dodetevevivusikidowozulo.pdfIn PDF document text
    • https://transdeliveris.lt/userfiles/file/nudowusumodenejevu.pdfIn PDF document text
    • https://drinkpoint.com/uploads/files/rebusananu.pdfIn PDF document text
    • https://nurea.se/currency/userfiles/file/fiwumevawiv.pdfIn PDF document text
    • http://olguanaokulu.com/upload/file/58057425265.pdfIn PDF document text
    • http://paradoxine.com/upload/files/20908933745.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/57rnc7nrgl0n91jhpvg3jgj0hq/3269319077.pdfIn PDF document text
    • http://l-max.ru/userfiles/file/bolaratoludexiz.pdfIn PDF document text
    • http://bulk-supplies.com/userfiles/file/65912656976.pdfIn PDF document text
    • http://ellissi.org/userfiles/files/62118064574.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146fc2729e33---56798662412.pdfIn PDF document text
    • http://dexgerm.com/data/file/userfiles/files/64722617555.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_off0000e874.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE874 11120 bytes
SHA-256: a27e08a93bf5191f4903f2305698c536606be7ee0885842ed6e6d74f6fd83818
font_01_sfnt_off00010240.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10240 19504 bytes
SHA-256: a134d42eaeebb2e50e7273eddcf73ebf1f8df976438bee467bce8e09d2d8efb5
font_02_sfnt_off0001351a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1351A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1