Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5c0f81ae618e9ed…

MALICIOUS

PDF

70.9 KB Created: 2021-07-14 02:34:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 051126987826e501079bde40acfb3224 SHA-1: cb5e596b7002ee83536ef6d2fffb10b73b18f7ce SHA-256: a5c0f81ae618e9ed054f754d43ef21bdab4c11443e6e503172385ea4f2dbd769
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites hosting other PDF files, indicating a link farm or distribution mechanism. The presence of multiple distinct hosts and the use of 'utm_term' parameters suggest an attempt to manipulate search engine rankings or distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/774d89556cdd4990e28835d58bf4e635/zokakufumuwupivu.pdf In PDF document text
    • http://f-kcc.jp/user_data/userfiles/files/2881588133.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607c21bceefe9---mimajabetoto.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16083a36177db3---nazudarazaruxaxufubibogi.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c03df6d76b4---67817607311.pdfIn PDF document text
    • https://activepymes.com/pub/file/vuxozoke.pdfIn PDF document text
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/61669425521.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/05d8f1972094e70777faf532601ea247/87417887816.pdfIn PDF document text
    • http://ginzaramen.us/uploads/files/40203940954.pdfIn PDF document text
    • https://capecoralliving.com/media/file/22659263004.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/23577078090.pdfIn PDF document text
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/ogtsqoqfsr9v5fvdjour4aqvv7/kusokoxirazovefawog.pdfIn PDF document text
    • http://primebrokeragetx.com/ckfinder/userfiles/files/67854024006.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/tizapumalatedosoni.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16097ffb75b3c3---65923267118.pdfIn PDF document text
    • http://mid-europe-ex.com/wekepoxeronumeder.pdfIn PDF document text
    • http://geredekombiservisi.com/userfiles/file/87082652661.pdfIn PDF document text
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/9677de4938ffb2f04e67d2859402a2a6/kejad.pdfIn PDF document text
    • https://ksboutlet.com/file/files/29050052973.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/92004177314.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608188aa59822---nekabemiwifedumad.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16096863fbf376---58276817972.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa7867f090---29487359828.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=chemical+equation+for+aerobic+respiration+in+plantsPDF 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_off0000b5ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5EF 14912 bytes
SHA-256: 7298cdfc8304171b6aad4fe023824f823d7d1bc9ab9ed165680f5ff26f692bed
font_01_sfnt_off0000dbed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBED 11164 bytes
SHA-256: 8ad1982dcb7c94e52bfed3bedf5ebc235f35076f138a54ee3e3c65cb295746a1
font_02_sfnt_off0000f59f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF59F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1