Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a08ceff15b943a0…

MALICIOUS

PDF

90.2 KB Created: 2021-09-11 05:22:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 84c5fe75c51182f53395c7867becd000 SHA-1: cd57a8be8910086d912aa4acf4456de680a0ca3a SHA-256: 8a08ceff15b943a0d99b160b2ab7ebd919044cea76c0418c76771553cdbbddae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs that function as a link farm, directing users to other PDF documents hosted on various domains. Several heuristics indicate this is a link farm on disposable or compromised hosting, and ClamAV detected it as a phishing trojan. The ML classifier also strongly flagged it as malicious. While no scripts were extracted, the structure and URL patterns suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://newtrichur.com/userfiles/file/libadaxivatozip.pdf In PDF document text
    • http://mtreurope.com/ckfinder/userfiles/files/76271623785.pdfIn PDF document text
    • https://webrobogo.hu/kepek/semitaxokofuwafopax.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/dosetopotapenexukurejew.pdfIn PDF document text
    • http://joyear.com/ckfinder/userfiles/files/57933450882.pdfIn PDF document text
    • https://tectrongim.com/uploads/files/xetavoki.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/lm58an6g7l7aipdpo6fmfl7dnq/62360114430.pdfIn PDF document text
    • https://halkum.rs/files/fukopijefiwup.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/50776746506.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/93153663641.pdfIn PDF document text
    • http://taiwangallant.com/uploads/files/202109081710385111.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/zafusejugo.pdfIn PDF document text
    • https://eko-briketes.lv/userfiles/files/4640175463.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/d84d7aad35616c10087b68e3853e9d36/66433104123.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/nchh2ktucmtohg4sv0dah4jj4d/zegapoxemutufosugurunewaj.pdfIn PDF document text
    • http://jatechkj.pl/upload/fck/file/50449887413.pdfIn PDF document text
    • http://onestep-tokyo.com/userfiles/file/63404387033.pdfIn PDF document text
    • http://transgusto.ch/userfiles/file/71592524850.pdfIn PDF document text
    • http://we2meeting.com/ckfinder/userfiles/publics/files/63099240158.pdfIn PDF document text
    • http://tomaszfilipczak.pl/userfiles/file/sadazo.pdfIn PDF document text
    • http://uni-farm.pl/ckfinder/userfiles/files/20969280691.pdfIn PDF document text
    • https://motodubai.com/uploaded_images/files/85436570883.pdfIn PDF document text
    • http://lechioutdoor.com/userfiles/file/nabipexolotunesaverede.pdfIn PDF document text
    • http://xindeshiye.com/uploadfile/file///2021090504480383.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=get+on+top+no+flashPDF 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_off00010016.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10016 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001182d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1182D 10300 bytes
SHA-256: 76cbe06158422bfca963f469477d556073d2b873d688e2502e25749d34bc3b60
font_02_sfnt_off00012f69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F69 17116 bytes
SHA-256: 4a06c29a5ea6a3f0e3013e0357655c28423bdc3373f17f9f59b051ed2fcd4273