Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0561742f414685f…

MALICIOUS

PDF

85.5 KB Created: 2021-09-14 02:13:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 7d182def80e85aed936a9e7fdf6884ff SHA-1: 0c350827eba1e432d16fddf64150598e1130da81 SHA-256: a0561742f414685fa70de981de9c1454ce994b27d9b29a156bf1bc2cea25750b
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. The presence of numerous unknown-reputation URLs suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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 https://nomylo.ru/uplcv?utm_term=spanish+beginners+pdf PDF link annotation
    • http://ck-tct.ru/userfiles/file/86064384770.pdfIn PDF document text
    • http://newo.ru/files/files/zakopuvujexuluwoginujuvux.pdfIn PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/kumudalibutamunewimijot.pdfIn PDF document text
    • https://slezanie.eu/userfiles/file/17093227578.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/32190009180.pdfIn PDF document text
    • http://bjavc.com/filespath/files/20210912122619.pdfIn PDF document text
    • https://walnutcreekguide.com/wysiwygfiles/file/pemetixagitimejegidefox.pdfIn PDF document text
    • http://koopmankennedyfeller.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/70313626218.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/161326006632ac---54889709965.pdfIn PDF document text
    • https://plewmal-d.com/Uploads/files/diwikekut.pdfIn PDF document text
    • http://winkeleninzundert.nl/uploadimages/files/56401686973.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/ximuxikaxifonoge.pdfIn PDF document text
    • https://suativisamsungtaihanoi.net/upload/files/pafufatijomawisap.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133455833075---48089367517.pdfIn PDF document text
    • https://www.prshots.com/ckfinder/userfiles/files/34843135604.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd40a45f45---jipor.pdfIn PDF document text
    • http://cinebuzz.be/uploads/userfiles/files/vanufituralamomagomedam.pdfIn PDF document text
    • http://harc-ias.vn/Images_upload/files/sefuzi.pdfIn PDF document text
    • https://centrorevisionimonregalese.it/file/sazadiledokizaxifekej.pdfIn PDF document text
    • http://dennehylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fivaxosujagigekupa.pdfIn PDF document text
    • https://allora-tour.by/var/upload/file/fukamaxapepekokajon.pdfIn PDF document text
    • https://xn--pssa17sw71b.tw/upimages/files/kusige.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_off0000e8f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F1 18472 bytes
SHA-256: ab8f93623506c96c01ee77b42cdac1f531447f681fd7786bac516207ef862505
font_01_sfnt_off00011876.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11876 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001308d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1308D 10728 bytes
SHA-256: 1528b19d1683a0c460fc6f5921ff709d8c8fc8b122925f7c493cd32f0ec5ab9a