Malicious PDF — malware analysis report

Static analysis result for SHA-256 856d42e24a245ca6…

MALICIOUS

PDF

72.1 KB Created: 2021-09-14 13:19:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 65af7739720dffbe3696a4b28808b25f SHA-1: 75a7ce3f3c6cd1b5fe7ad6daf5e5010a0e97ceb7 SHA-256: 856d42e24a245ca6f88be24d7f7fc564b1e431bd84374bfdda4a63b16786d4ab
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure and URL analysis are sufficient to infer a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://catamma.ru/uplcv?utm_term=how+to+spoof+pokemon+go+2021 PDF link annotation
    • http://security-m.jp/tool/images/file/jevedituzid.pdfIn PDF document text
    • http://ncfc.com.tr/ckfinder/userfiles/files/wuvonubabavedevuxi.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613d4eda927e1---jojepema.pdfIn PDF document text
    • http://tokyoto.pl/UserFiles/file/6965736836.pdfIn PDF document text
    • http://eiffelflowersquesnel.com/userfiles/file/wonoburujepugisexa.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/48280950728.pdfIn PDF document text
    • https://nhahangphongcanh.com/uploads/files/76192613523.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/95087543321.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8a637570e---pikez.pdfIn PDF document text
    • http://consorzio-csa.it/userfiles/files/3527412296.pdfIn PDF document text
    • https://olgunbey.com/upload/ckfinder/files/60077545400.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021091315132136.pdfIn PDF document text
    • http://angerdress.store/ckfinder/userfiles/files/zawenax.pdfIn PDF document text
    • http://xn--80aaaaadfwa5aftjhxrkcrg8iwc.xn--p1ai/pict/file/30985299661.pdfIn PDF document text
    • http://m2m2design.com/userfiles/90459439420.pdfIn PDF document text
    • http://benly-carson.com/product/files/voluwemoretulax.pdfIn PDF document text
    • https://auto826.com/uploads/files/guzozewudapexazapa.pdfIn PDF document text
    • http://winhazel.com/indigo/ckfinder/userfiles/files/sezukonudujowudezexes.pdfIn PDF document text
    • https://eownauto.com/uploadpic/files/26010139475.pdfIn PDF document text
    • http://vasset.bg/userfiles/file/97617955616.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613c016b689da---14073643498.pdfIn PDF document text
    • https://locktactyuma.com/userfiles/file/98334478263.pdfIn PDF document text
    • http://kor-ra.ru/UserFiles/file/jumav.pdfIn PDF document text
    • https://venusnvs.com/userfiles/file/ludekomamigufepujazis.pdfIn PDF document text
    • https://rjpexport.com/files/50490734743.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_off0000b540.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB540 17492 bytes
SHA-256: 5d8b7a0a29db4bbdb377cf8c67813ca2f62d15deaa6326d0235d36d2e7d3101b
font_01_sfnt_off0000e1fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fa11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA11 10764 bytes
SHA-256: 950631f60ecf5ad8b4694b581dddb0d53a14ac66887166f90c7f033edb6fe3ef