Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4e4aae76461af44…

MALICIOUS

PDF

72.0 KB Created: 2021-09-26 00:47:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 7aa42faf3bc462dfc73c2c10d7b8d210 SHA-1: 35c4223c301f744a41ebcc8747a7722fb48d20cf SHA-256: f4e4aae76461af4478283329fb189e148002e2d5df9f30078ec833e3f47d0fe8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm pointing to multiple PDF files hosted on various domains, with a notable heuristic indicating a compromised WordPress upload storage. The document body is unreadable, but the heuristics suggest the primary function is to redirect users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/161471986640e1---753406903.pdf In PDF document text
    • http://gesundheit-im-blog.de/userfiles/file/59237574733.pdfIn PDF document text
    • http://fishtech.org/uploads/userfiles/file/file/86098352463.pdfIn PDF document text
    • https://vinamex.info/uploads/news_file/bazazegulovaxatovopezavu.pdfIn PDF document text
    • http://ducthanhtam.com/uploads/userfiles/file/timitupe.pdfIn PDF document text
    • http://americandeliorder.com/uploads/files/5705507005.pdfIn PDF document text
    • http://machinesupplier.cn/data/product/file/2021918_114759_252.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/b2bdv9divvue13mq3gqfmi9ot5/45991891868.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/pozitamone.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021090407123974.pdfIn PDF document text
    • http://perfect-gallery.com/userfiles/file/72925872820.pdfIn PDF document text
    • http://xn--9i1b14lzokxjcrti5um.com/upload/fckeditor/file/tukadavuvijazunubeze.pdfIn PDF document text
    • https://umiyawoodworks.com/fckdb/userfiles/file/43012011426.pdfIn PDF document text
    • http://www.moyekolodin.com/files/nitebofizezoleduzitevira.pdfIn PDF document text
    • https://naveenent.com/administrator/imagetemp/file/93340317856.pdfIn PDF document text
    • http://rideco.hu/upload/file/74618147741.pdfIn PDF document text
    • https://bibliotheque-des-arts.ch/ckfinder/userfiles/files/30080987961.pdfIn PDF document text
    • https://zohopinler.com/calisma2/files/uploads/xinivumilebomovigonute.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/ha02vequfof13jtpgl1ibl177q/bizikodavin.pdfIn PDF document text
    • http://tecsun-moscow.ru/docs/file/nogupep.pdfIn PDF document text
    • http://erfanekeshmiri.ir/userfiles/file/feduwigedodededod.pdfIn PDF document text
    • https://itandem.net/ckfinder/userfiles/files/55165869060.pdfIn PDF document text
    • http://mh-gartengestaltung.de/userfiles/file/mabixub.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=how+to+get+text+messages+on+computer+from+androidPDF 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_off0000b2cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cae3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAE3 11196 bytes
SHA-256: d2fc870cc7f50be8918165e08e2c47c0c0a9bc803ee59cb9530d76217f5888b9
font_02_sfnt_off0000e4eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4EB 17892 bytes
SHA-256: cd9920e42cdd4e3bc98a5da2408a0c68ffa29a333f3d5a00331adc2e69852dda