Malicious PDF — malware analysis report

Static analysis result for SHA-256 a828686a18b3125b…

MALICIOUS

PDF

102.5 KB Created: 2021-09-02 05:20:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e36399ee80dc9311e9917d549256fcff SHA-1: f448bbca884961b2170abd5f589948c4c85937ef SHA-256: a828686a18b3125b8232dae400aba20e863789fd1b0ad6e2499d37cb37a1ce45
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to compromised CMS upload directories. The ML classifier and ClamAV also identified it as malicious, specifically a phishing trojan. The document body was unreadable, but the presence of numerous links to potentially malicious sites indicates an attempt to redirect users to phishing or malware distribution pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ababe78c894---39376459223.pdf In PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071e80d0a85d---kofoziwuwapizoronarewezor.pdfIn PDF document text
    • http://mrsjamesirvine.com/clients/82887/File/dusemaxitigudevojakuj.pdfIn PDF document text
    • http://ibb-online.ru/f/file/65285059742.pdfIn PDF document text
    • https://chungcungoaigiao.net/uploads/files/68303608024.pdfIn PDF document text
    • http://travelport.pl/userfiles//file/rojofoti.pdfIn PDF document text
    • https://eniedu.com/data/file/20210828192145.pdfIn PDF document text
    • http://c2r-auto.com/uploadfiles/file/2021060723014873499.pdfIn PDF document text
    • http://aitrans.org/UploadFile/file/F1202106201653307180.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d9eaf237a36---82855914842.pdfIn PDF document text
    • http://leise.ru/admin/ckfinder/userfiles/files/57101281748.pdfIn PDF document text
    • https://evergreencans.com/userfiles/file/87852970117.pdfIn PDF document text
    • http://headrepublic.pl/images/files/17912423055.pdfIn PDF document text
    • https://thefertilizerequipment.com/d/files/5268305506.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/xewapokibugonuvub.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/5c0ccfa14a5e085490d5c02878cf7f39/43849512254.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/patagejobuviji.pdfIn PDF document text
    • http://elektrostroy.kz/ckfinder/userfiles/files/bekul.pdfIn PDF document text
    • https://marosme.ro/hirek/file/72277932867.pdfIn PDF document text
    • https://artasedanasingaraja.com/uploadfck/file/27009914927.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/e1e214e5b339b38f8475f0b7577ac769/ronawanojivegedovopowexin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=square+root+of+832PDF 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_off0001286c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1286C 20040 bytes
SHA-256: 0f2d10f1efcd5719d0a9ce29cd2267ad71243d2e6e2ddad5d7a4a6eb7d2fb22f
font_01_sfnt_off00015c6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15C6D 10620 bytes
SHA-256: 66eb17c3d55504a70ca060f2ffaade62c99b8680a1cfc10f6b3c92c7fef38412
font_02_sfnt_off000174f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x174F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1