Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d41aa87c88ace59…

MALICIOUS

PDF

73.7 KB Created: 2021-06-29 23:52:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 61e1714e658962678bc2de7ba405f321 SHA-1: ba6f0987d01d23eb382feb753181a684e76092bc SHA-256: 4d41aa87c88ace5911165c7e9f223b79a7f7e575ab0c8c3d01eb8f0a1e8cf900
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to compromised WordPress upload directories across various domains. This structure is indicative of a link farm, likely used for SEO poisoning or to distribute malicious payloads. ClamAV detection and ML classification strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ae8094b85d7---1586094590.pdf In PDF document text
    • https://travolution.travel/wp-content/plugins/super-forms/uploads/php/files/53676d827e191edadc43df03831bc060/12005735184.pdfIn PDF document text
    • http://ztkammer.at/uploads/file/4211148366.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/fudisasujisev.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/c046110bfab904a71dd340453d58f3af/torivibazetuvebabix.pdfIn PDF document text
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/bfvajpa3b0mogku6iugr8sg2j5/rupop.pdfIn PDF document text
    • http://lagostena.it/userfiles/files/buzalalatitedajup.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/9b0a26233d24bfdf2f4f4fdf891ce646/fubapukodeg.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16081e228d9641---66685895287.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/8dfe76a068ff5ad97dc376f93c377246/18399886401.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/2abf10182427178cfbf290a06128810f/69756447812.pdfIn PDF document text
    • http://www.look4job.gr/images/_user_na/file/37343053107.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607be8beaefa0---nexigulunatew.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/19fc05462e8e092b55ccbe988f8be1fe/gepefewas.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eabda63b01---bawodaxiropisadirizo.pdfIn PDF document text
    • http://olddieselparts.com/ckfinder/userfiles/files/rabapifarekuvesubewuj.pdfIn PDF document text
    • https://carea2plus.com/wp-content/plugins/super-forms/uploads/php/files/d4330e3a85cbbd680ee0b9135456757e/mujuwetikexen.pdfIn PDF document text
    • https://palcev.ru/userfiles/file/85714858713.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160967016455d6---74275398906.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/32c718c6753a1418e3363cd5f316cd11/tananilisosiza.pdfIn PDF document text
    • http://stardentalcare.org/userfiles/file/78113177162.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/2190f417c3b7d1e962773a199a52a9a5/93554928569.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16081ddaf23bf9---dorafebibanobafixelax.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/vj2q90k5otfesb3gl11db2ocsq/ponenajizaxiweledodirope.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=after+adorno+rethinking+music+sociologyPDF 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_off0000beab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEAB 11208 bytes
SHA-256: b739674af0534234480fdc30522b4794243b0b7061aac7974011eb0418513fc2
font_01_sfnt_off0000d88b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD88B 15776 bytes
SHA-256: b46208a2cc60f7ddf1c6fe9b5888d59c1cab73c19228c65eb9ea79e9de94709d
font_02_sfnt_off0001011d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1011D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1