Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c33d8637dc2b04a…

MALICIOUS

PDF

97.3 KB Created: 2021-09-17 19:46:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6de89e5c98319d95a8255c72c4c43bb0 SHA-1: 21cef123b7c91c7bd97927a5c85d5a33e3bfdd3d SHA-256: 0c33d8637dc2b04ad42955d650c9d1aa68ed2b5c64bfd8b2ed5a527b833ce98d
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm. Multiple external URIs are present, pointing to various PDF files hosted on what appear to be compromised CMS upload directories. The document body is heavily obfuscated, preventing a clear understanding of its direct intent beyond hosting these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://drafthe.ru/uplcv?utm_term=filmyzilla+the+tomorrow+war PDF link annotation
    • http://p-itos.net/admin/userfile/image/file/mosutebe.pdfIn PDF document text
    • http://strojsteel.cz/webpagebuilder/ckfinder/userfiles/files/47971002036.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/duzuzetibewofuw.pdfIn PDF document text
    • http://ipcmanpower.com/admin/style/images/userfiles/file/gakuridumaxawifu.pdfIn PDF document text
    • http://yournamebadges.com/withyourdog/cms_uploads/file/paniwemeviwanipiman.pdfIn PDF document text
    • http://186086.com/upload/files/54185689839.pdfIn PDF document text
    • https://jdrum-music.com/uploads/ckfiles/files/88313888826.pdfIn PDF document text
    • http://otestmanager.org/club/data/userfiles/file/20210901180414.pdfIn PDF document text
    • http://keyday.ru/files/files/32543685993.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e5feb2d424---46809205867.pdfIn PDF document text
    • http://safarang.com/basefile/files/89297992029.pdfIn PDF document text
    • https://gospel-streams.com/asset/ckfinder/userfiles/files/65888964689.pdfIn PDF document text
    • https://slezanie.eu/userfiles/file/77673466608.pdfIn PDF document text
    • https://sarvodayasamaj.uk/upload/files/96526300700.pdfIn PDF document text
    • https://tspinstruments.com/cache/fck_files/file/bigutudu.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba82b95ea5---vumibibigosilebe.pdfIn PDF document text
    • https://mehregancenter.ir/images/upload/files/zurisef.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/161320d5a35905---jobulolimatiteg.pdfIn PDF document text
    • http://henskeschildersbedrijf.nl/upload/vafobekikuni.pdfIn PDF document text
    • http://soc-in.com/data/media/files/19357934479.pdfIn PDF document text
    • http://poliinc.com/upload/files/96354381363.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_off0001179f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1179F 18856 bytes
SHA-256: 7c2a9bcd5496499bdb32b8d89b943947649ff31d55bb2df280b93b5653b4513d
font_01_sfnt_off000147cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147CC 10336 bytes
SHA-256: 65a243fb0d5304941a0d4fafd304f596b3c5a4205a73250868d324f259dde466
font_02_sfnt_off00015f2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15F2D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1