Malicious PDF — malware analysis report

Static analysis result for SHA-256 55b0028fc5e47796…

MALICIOUS

PDF

85.0 KB Created: 2021-10-08 00:52:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aa7d9c4747e040638500849046e01834 SHA-1: 5e2773c7c88d3a1d7d0fa5af72207017f0422252 SHA-256: 55b0028fc5e47796d28da25cc1ca54a050bd5c25131224511cde93986e11876e
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised CMS uploads or disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure suggests a lure to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://verlauf-ekb.ru/admin/ckfinder/userfiles/files/selimi.pdf
    • https://alice-immo.com/userfiles/file/97347565506.pdf
    • http://xn--9w3b270a7kf.kr/data/editor/file/73136535734.pdf
    • https://motoquadro.de/userfiles/file/23889087859.pdf
    • http://ucg-eg.com/userfiles/file/57752740250.pdf
    • https://aihr-iadh.org/uploads/FCK_files/file/gubewigunarokagexebo.pdf
    • http://uptindia.com/newsimages/file///lejomugifulosi.pdf
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/4309133346c6563073b297e1b0e76cc1/81876458150.pdf
    • http://reklamavysocina.cz/UserFiles/File/76721590455.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146c949069c1---ragatatawu.pdf
    • http://s13cf5ef.alojamientovirtual.com/ropadefutbolbarata/userfiles/file/81498405948.pdf
    • http://foto-klub.dk/userfiles/file/68956798012.pdf
    • http://nieruchomosci-swidnica.pl/userfiles/file/mepivifumuworewujuv.pdf
    • http://odnoklassniki-files.ru/images/uploads/files/23137556432.pdf
    • http://www.extramas.com/userfiles/files/95211036387.pdf
    • http://trunglamdecor.com/uploads/userfiles/file/2109332909.pdf
    • http://parikshitconstruction.com/uploads/9336257286.pdf
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615895853ed5c---puvefunosa.pdf
    • http://tamphuhiep.com/Images_upload/files/fugenilodapasovelopuviwol.pdf
    • http://chupanhnoithat.vn/upload/files/4378391156.pdf
    • https://postelezmasivu-liberec.cz/ckfinder/userfiles/files/relad.pdf
    • https://adikkeempat.com/contents/files/19774437766.pdf
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/24aidfad64di3vq9du20u736g2/lujewerofidoruturet.pdf
    • http://klenderbio.com/upload/files/pojategelu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=the+creation+of+patriarchy+chapter+11+summary
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1a1.bin
98748fc9c0bc9c33e125b2289acb34acaa587790952d6139967a1faecc5a979e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1A1 10928 bytes
font_01_sfnt_off0000fae0.bin
6ef0fda6c7701ac96fd8558984e07674d633cda68ffa23f740fce6d02ab5bcec
pdf-font-stream PDF embedded font (sfnt) at offset 0xFAE0 19328 bytes
font_02_sfnt_off00012e17.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E17 16792 bytes