Malicious PDF — malware analysis report

Static analysis result for SHA-256 d71637620c48e3d5…

MALICIOUS

PDF

71.3 KB Created: 2021-09-09 19:46:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 305f63c5aa7091a483e2308331e8c267 SHA-1: ab8d253e28f1e45843995a5bf43e233677ff3118 SHA-256: d71637620c48e3d5cee6c4298bd97b97978657b0cb63d8220264c0c208e6d941
156 Risk Score

Malware Insights

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

The PDF contains a significant number of external URIs and link farms, many hosted on what appear to be compromised or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF designed to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://philabc.ru/uplcv?utm_term=construct+2+for+android
    • http://aihyang.com/userfiles/file/pagaderoso.pdf
    • http://ncteonline.com/userfiles/file/joraripema.pdf
    • http://mim2010.ru/userfiles/file/xunifizenefufawowijek.pdf
    • http://tnhmc.com/userfiles/file/finikefosefaru.pdf
    • http://beijingxinzhi.com/userfiles/file/20210903023328_682951366.pdf
    • http://studiomarazzi.eu/userfiles/files/bemavewop.pdf
    • https://groupunsur1.com/contents/files/40359048449.pdf
    • http://the100voicesofgospel.ch/fichiers/newsletter/file/fitidovomipa.pdf
    • http://fittbikese.hu/files/file/13951624233.pdf
    • http://i-akparat.kz/ckfinder/userfiles/files/54645953337.pdf
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161328a66749e8---23970496870.pdf
    • http://safarang.com/basefile/files/17206722161.pdf
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/a188fb62bc3225c0f8dc59f1a5437779/bulirematuresilukukep.pdf
    • https://ceccardolj.ro/userfiles/file/17815005198.pdf
    • http://elverum-revmatiker.no/images/file/74997165564.pdf
    • https://hospvetcentral.pt/site/upload/file/64780450051.pdf
    • https://minlinart.com/archive/upload/files/95282644357.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/16132b023dca77---4549003846.pdf
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/62117c38cb2b76dac7b3f809ae6e138f/23737467436.pdf
    • http://molenat-energies.fr/molenat.com/images/editor/file/kufeworutusedukabagesijiv.pdf
    • http://agapetown.net/ckfinder/userfiles/files/36620969473.pdf
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613533d6b606a---75634760403.pdf
    • http://juditphotography.com/picture/userfiles/file/33893438400.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b12a.bin
f1cf53ca7b21a78540f07baf31bc157777e2d27b05e4e6df7bc68515719b0a4f
pdf-font-stream PDF embedded font (sfnt) at offset 0xB12A 18264 bytes
font_01_sfnt_off0000de09.bin
18bce9ac2f442a6c71464f9f59e48322221054869e8b6f62033ee4460cb0751e
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE09 10540 bytes
font_02_sfnt_off0000f652.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF652 16792 bytes