Malicious PDF — malware analysis report

Static analysis result for SHA-256 91f8aec64a87efde…

MALICIOUS

PDF

68.8 KB Created: 2021-09-29 00:45:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7f7f1e55eeaacfa7feb5a1b6c612d145 SHA-1: 5c345a07f160c55ddcc602fb595e291f4dbf707c SHA-256: 91f8aec64a87efde454dbcad0a7c6bb13d66833ee810de20be60c646e0b6c879
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The embedded URLs, such as http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/161444c0811af7---novilumojadewuderunagek.pdf and https://medgal.pl/admin/ckfinder/userfiles/files/gasogupani.pdf, are likely part of this malicious distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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 https://medgal.pl/admin/ckfinder/userfiles/files/gasogupani.pdf In PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/161444c0811af7---novilumojadewuderunagek.pdfIn PDF document text
    • http://onestep-tokyo.com/userfiles/file/98860326142.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210928020842_o68csm.pdfIn PDF document text
    • https://dtd.com.pk/ckfinder/userfiles/files/95306494669.pdfIn PDF document text
    • http://khocabien.com/uploads/files/vidujemalisejoji.pdfIn PDF document text
    • http://atthaya.com/file_media/file_image/file/59291809067.pdfIn PDF document text
    • http://stilna-ya.com/_userfiles/file/80330885890.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/27652783926.pdfIn PDF document text
    • https://www.funes.gob.ar/ckfinder/userfiles/files/torokaton.pdfIn PDF document text
    • http://pcwenhua.com/uploadimg/file/1631869082965444485.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/b2bcaaced31c124003bc482974dc5d14/12407040629.pdfIn PDF document text
    • http://ballmillfactory.com/d/files/nofisebepesefotuwara.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613efa2ac1177---dufaxojukivubigevoga.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/38159120984.pdfIn PDF document text
    • http://atem.sciara.eu/public/upload/file/47870610551.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021090210361848.pdfIn PDF document text
    • http://akvarium-olbrecht.cz/upload/file/34378333568.pdfIn PDF document text
    • http://byecook.com/ckupload/files/45930826897.pdfIn PDF document text
    • http://huyminhplastic.com/upload/files/mobumozizixakanexusemaxu.pdfIn PDF document text
    • http://cuathepvangohaiduong.com/images/ckeditor/files/51050237828.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=apokolips+war+streamingPDF 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_off0000aee0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEE0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c6f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6F7 10752 bytes
SHA-256: bf864f2f5c6f472e5f66f41a716fe06e8bf4e4bf4b8dff50c4748b05bb16dc32
font_02_sfnt_off0000dfcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFCC 15032 bytes
SHA-256: 37b511819e1f02b865c3ede55ab6b90eb88e8c9eac07ba50550f32a231a627e1