Malicious PDF — malware analysis report

Static analysis result for SHA-256 25668b1c91679f01…

MALICIOUS

PDF

88.4 KB Created: 2021-07-24 01:47:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 4dced3c9cae104f66aff786bddccfe72 SHA-1: 8706c5e85d78ea7d9427c2cc20fac63726cff84a SHA-256: 25668b1c91679f015f75dbcefeee4279fa79475b649aee2a6d2d91616bbe541a
156 Risk Score

Malware Insights

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

The sample was detected by ClamAV as a phishing trojan and flagged by an ML classifier. Heuristics indicate it functions as a link farm, pointing to multiple compromised websites and disposable hosting. The PDF document body is heavily obfuscated, suggesting it is not intended for direct user interaction but rather to facilitate the redirection to malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://mea-travel.pl/userfiles/file/noxedatolekenolak.pdf In PDF document text
    • http://hanart21.com/files/userfiles/file/77181787823.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/37fe8fa1c12550667f51803be0f67032/47002364636.pdfIn PDF document text
    • http://doverhighschoolhalloffame.com/clients/2/2d/2d76883e1086210ef8e2c43836b0327f/File/juminad.pdfIn PDF document text
    • https://sardavetri.it/userfiles/file/xurabinagiva.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b610533c874---vezagasebazikovomelibipav.pdfIn PDF document text
    • https://fertilizergranulatorprice.com/d/files/subebitojefobu.pdfIn PDF document text
    • http://clarkstownhs64.com/clients/2/25/255c49a504cbad61718694d8b78dfcdd/File/naxinagoguxotivazij.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/jubipiwumomamaxuvaw.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///59927065905.pdfIn PDF document text
    • https://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607ccb5918928---vavexatabunawifu.pdfIn PDF document text
    • http://ddrwc.net/clients/869849/File/zemibelofifemibara.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c668de7a6cb---mibobodapotep.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/d955f548879c78a52e4397578c2ef8aa/bedegulavosituk.pdfIn PDF document text
    • https://medtek.vn/storage/file/duranalirakux.pdfIn PDF document text
    • https://an-professional.ru/img/files/file/9899670604.pdfIn PDF document text
    • http://mitchelllawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/92103863150.pdfIn PDF document text
    • https://k-barrierfree.com/FileData/ckfinder/files/20210710_FEA77264282A000F.pdfIn PDF document text
    • https://rowadalbyt.com/userfiles/files/zewidabupejor.pdfIn PDF document text
    • http://asckhn.com/acskhn/userfiles/file/61224316126.pdfIn PDF document text
    • http://cukiernia.eu/upload/files/nupis.pdfIn PDF document text
    • http://ampletrekking.com/userfiles/file/tivajutibupav.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16087e029a16f2---49848820339.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/d21bef625e2fbdba84423d6c4e40d322/fazugixiga.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=business+proposal+powerpoint+examplePDF 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_off0000f46f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF46F 17408 bytes
SHA-256: dc7f497badfb1159f577ed9ade30fefda136537c51f726e46676191e3cf0b410
font_01_sfnt_off0001222e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1222E 10752 bytes
SHA-256: 7ea2a0f2f76ed2e3e2072635247c79a6ae3d2f5a0a84355760da6b8b517c894f
font_02_sfnt_off00013b00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B00 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1