Malicious PDF — malware analysis report

Static analysis result for SHA-256 aac8a6d2b6411d33…

MALICIOUS

PDF

88.0 KB Created: 2021-08-09 06:41:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 1fa1c182a3d3e65f19b4593e86450459 SHA-1: 9468c4b03566f0f993926659822834838295a72f SHA-256: aac8a6d2b6411d33fcbf666778c7cda133977d97a4d63d30e4ff158b602ed6f2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of links, many pointing to compromised WordPress upload directories, suggesting it's designed as a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were extracted, the structure and URL patterns are consistent with a malicious document designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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
  • 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://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160872cb2bbecf---pifulob.pdf In PDF document text
    • https://ourlady-schools2.com/userfiles/files/bigexuxazeduvulat.pdfIn PDF document text
    • http://euroambulans.pl/userfiles/file/27790787794.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606d43818ecc9---41984776930.pdfIn PDF document text
    • https://arerp.kr/data/file///vulavuver.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/13fad5ae514f8f15a0cc6b0bbb47219e/sejoxatetix.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/160906410adb36---10513901123.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096e03e6fbe7---81568288103.pdfIn PDF document text
    • http://olddieselparts.com/ckfinder/userfiles/files/wovivadisasiponutaja.pdfIn PDF document text
    • https://sanipacific.com/attachment/file/tafisojowufugemijikid.pdfIn PDF document text
    • http://pawsandtiaras.com/ckfinder/userfiles/files/jumimezet.pdfIn PDF document text
    • https://mycocoa.org/images/upload/files/20166786612.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b1084155235---medolazolufufukagiguba.pdfIn PDF document text
    • http://host.keraladreamhomes.com/~viswabrahmathach/admin/fckeditor/editor/filemanager/connectors/php/userfiles/file/70273142130.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/730l77m5tjq7p3fjiu3h34c5iu/68177923118.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607120431fd5d---45641695850.pdfIn PDF document text
    • http://khachsansapa.vn/webroot/img/files/3843383650.pdfIn PDF document text
    • http://outspokenholland.com/userfiles/fckFile/20210522011146.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c8f193af1ea---ruramixawobenupi.pdfIn PDF document text
    • https://alsterparkett.de/wp-content/plugins/super-forms/uploads/php/files/b0ovge8qvf98o2vborlqcgle7u/peparovakujej.pdfIn PDF document text
    • https://bnbcostaverde.it/userfiles/file/14966342269.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b96ce810500---sasifunufamifa.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608863d361394---41754423838.pdfIn PDF document text
    • http://chothuexeninhbinh.net/data/dulieu/files/15072310075.pdfIn PDF document text
    • https://tarzminder.com/resimler/files/9951010956.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160beba1f075b9---68899793256.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=que+es+un+monomero+y+un+polimero+ejemplosPDF 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_off0000f377.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF377 17596 bytes
SHA-256: cdc849a63d00a9e547530b82a7abc680f0f761acb034817f2d4fe914a3da90de
font_01_sfnt_off00012027.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12027 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001383e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1383E 10556 bytes
SHA-256: 88930fcc5e73fe62fa6e4c6802c62bcba38a3063b750fc02449ed541371b594b