Malicious PDF — malware analysis report

Static analysis result for SHA-256 757ca298cb82e616…

MALICIOUS

PDF

76.3 KB Created: 2021-09-17 22:07:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e4ea5da90945c23cb44b259e2c390638 SHA-1: f3fb35ae8a1612c7bc8f0c847df06823332f18e1 SHA-256: 757ca298cb82e616118ae7a63a35e870210eb1999e71064d4c7f61908d8216f0
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting a link farm or phishing lure. The document body is heavily obfuscated and unreadable, but the presence of external URIs and link farm indicators strongly suggests a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/69631caf1ff810cc01ae049e9ff5bcf5/58788406003.pdf In PDF document text
    • http://pietroquatriniarchitetto.eu/userfiles/files/61209299090.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/861db8ef866575eda867367dbd246043/xiwesenitixutuzad.pdfIn PDF document text
    • http://ez-surveying.com/htdocs/cljr/data/files/28524095859.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/26585095958.pdfIn PDF document text
    • http://terezszilvia.com/images/uploaded/file/77525318213.pdfIn PDF document text
    • https://jiu-hang.com/upfiles/editor/files/15754327555.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b96e1af075---tonapimusetedekivepilewu.pdfIn PDF document text
    • http://nceed.kr/pds/userfiles/files/74722565884.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/56f1736683bc0c1d21741c1f2dd5a96b/58887817978.pdfIn PDF document text
    • https://giverny-bkk.com/upload/files/80145711093.pdfIn PDF document text
    • http://swancentive.com/cote_dor_import/admin/ckfinder/userfiles/files/pikalirok.pdfIn PDF document text
    • http://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/kudisarepesuvonimodidure.pdfIn PDF document text
    • https://www.tamilsaga.com/ckfinder/userfiles/files/vebanewowutonuz.pdfIn PDF document text
    • http://9y.bfage.com/upload/files/20210907101655.pdfIn PDF document text
    • https://nls.vn/upload/files/89024069947.pdfIn PDF document text
    • https://cytokin.ca/upload/editor/file/lifevebowopefipot.pdfIn PDF document text
    • http://ufnk.fr/app/webroot/files/file/59690863694.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/5154b9cc33552e563453a0e3ca4416d4/vimimi.pdfIn PDF document text
    • https://nazrabilisim.com/calisma2/files/uploads/11801634222.pdfIn PDF document text
    • https://next-engineering.com/userfiles/files/wugibe.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16142558a739e7---denaselitijawozik.pdfIn PDF document text
    • http://alessandrobelleseveterinario.eu/userfiles/files/daxagulosageleseba.pdfIn PDF document text
    • http://khocabien.com/uploads/files/74358541218.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=9th+physics+textbook+pdfPDF 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_off0000c82a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC82A 16508 bytes
SHA-256: 2b3e153d7767f8ac0109c717b32cb9919fe8326865fbe8c86cad3ddee65e70f7
font_01_sfnt_off0000f2a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A4 10824 bytes
SHA-256: a1939e4e5e5a359c8d164a564c25817e8c9d5236f7ac38d091ac60b971bf242b
font_02_sfnt_off00010b9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B9E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1