Malicious PDF — malware analysis report

Static analysis result for SHA-256 91377b8c67c41f16…

MALICIOUS

PDF

70.6 KB Created: 2021-09-07 08:52:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 7e896d168341d4fa96fe5bbf20722745 SHA-1: 8e506e4c1f079dd3757224648f4f0a558dc77d5b SHA-256: 91377b8c67c41f160a19c37e6e0539d7726b6fc96fed8b11f64261b56f9b85ed
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external links, many of which point to compromised websites or disposable hosting, indicating a link farm or SEO poisoning attempt. The ClamAV detection and ML classifier also flagged this file as malicious, specifically as a phishing trojan. While no scripts were explicitly extracted, the nature of the links suggests the PDF is designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5076

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
  • 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.
  • 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://falls67.com/clients/50406/File/sisifuvaxelojojozodaw.pdf In PDF document text
    • http://sovaimm.it/userfiles/files/29687986482.pdfIn PDF document text
    • http://pusulacampeyzaj.com/images/media/files/zarikixudegoduxuvafuwi.pdfIn PDF document text
    • https://moto-trend.cz/public/files/fck/file/56769533262.pdfIn PDF document text
    • http://andreaslasnik.com/data/files/talulokesofugoxasit.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160babe3b191f3---13927589750.pdfIn PDF document text
    • http://esistore.de/userfiles/file/bibixotogaxu.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cf1485f1f15---53528091541.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7c9a6c7bdd---50972994021.pdfIn PDF document text
    • https://ngoctraithaibinhduong.com/uploads/news_file/tufenotabonina.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c54eae05ce---ralemix.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094887a5f1bd---zutobukosegodujelelozive.pdfIn PDF document text
    • http://sarljarry.fr/userfiles/file/25765779257.pdfIn PDF document text
    • http://rszm88.com/upfolder/e/files/20210615021011.pdfIn PDF document text
    • http://manhchenang.vn/webroot/img/files/dazat.pdfIn PDF document text
    • http://airholic.com/UpFiles/WebEditorFiles/file/xupesivokopavev.pdfIn PDF document text
    • http://ues-rb.ru/themes/ues-rb.ru/files/zokumiwununej.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/fb737947e4fd935b4762fa8341ff1846/97090212399.pdfIn PDF document text
    • http://litho-and-co.fr/ckeditor/upload/files/51304157384.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa098b8d341---95330251175.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/23575840693.pdfIn PDF document text
    • https://hr-serdahel.hu/images/file/wenan.pdfIn PDF document text
    • https://avonsteel.com/UserFiles/file/43354240387.pdfIn PDF document text
    • https://istanbularicilikfestivali.com/upload/ckfinder/files/xuxis.pdfIn PDF document text
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/69058922700.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=vegetables+information+in+marathi+pdfPDF link annotation
    • 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_off0000b47a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB47A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC8C 18208 bytes
SHA-256: 951ec19a6130bc46853d54d0bb6876607cc3b4ae1a851f33a0ed7971c777284c
font_02_sfnt_off0000fb94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB94 11052 bytes
SHA-256: 5a8443b0651729485a1a977b6bf6485897d2a1130c74c125631d1bf89bb87957