Malicious PDF — malware analysis report

Static analysis result for SHA-256 da5c8b67425a083a…

MALICIOUS

PDF

72.2 KB Created: 2021-09-15 12:06:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a45fe23cc94929babe00fcd8d15d3b55 SHA-1: aecb337c11d4ea92e93f66d0cf1f3e43ac5e0e32 SHA-256: da5c8b67425a083a026bf20773002dbc1a94b57ab5642b340504eea514d4db29
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the extensive use of external links is a primary indicator of the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nomylo.ru/uplcv?utm_term=assassin%27s+creed+chronicles+india+apk
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16138079251b9b---wubabatokokigoko.pdf
    • https://silverstonedevelopments.com/ckfinder/userfiles/files/kubowup.pdf
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/f69a26788cb74950280c28d632de4fc9/77805414259.pdf
    • http://lungshingcentre.com/userfiles/61072598268.pdf
    • https://nhatngudongkinh.com/upload/ckupload/files/kafutuxiwakizazebapido.pdf
    • https://classoft.ro/userfiles/file/katofumosuvemadoguz.pdf
    • http://wsmr.us/userfiles/file/famowugowakeleguti.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1613483ce54875---63438874071.pdf
    • http://nutronicltd.com/userfiles/file/59381737968.pdf
    • https://groupunsur2.com/contents/files/mufogeselalezinosijekukev.pdf
    • http://viettranslators.com/webroot/img/files/68841697788.pdf
    • http://drigungkagyurinchenpalbarling.org/upload/userfiles/files/94165425318.pdf
    • https://jv-cms.crazy-jessie.nl/uploads/files/mimubiwidofu.pdf
    • http://babijie.com/upload_fck/file/2021-9-7/20210907135025973886.pdf
    • http://gsmontaggi.it/userfiles/files/mefepibuwip.pdf
    • https://scavilecis.it/userfiles/file/65622169874.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613002af691e2---nulefebadimejujaga.pdf
    • http://jinanxintiandi.com/userfiles/files/90272551006.pdf
    • https://homestayhoian.vn/uploads/image/files/44363359669.pdf
    • http://tovicetour.com/FileData/ckfinder/files/20210911_422288D42DAF3C4A.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138e15f3eb06---soditamawokokowuwo.pdf
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac640f1d72---72428916080.pdf
    • http://clair-environnement.eu/catalogue_dynamique/file/bojatijemugukasiwixakuj.pdf
    • http://villa-margherita.biz/userfiles/files/tuxemivovezojoxabet.pdf
    • http://www.badischer-kunstverein.de/ckfinder/userfiles/files/nowepoduxisagejuxerij.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_off0000ba8e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBA8E 16792 bytes
font_01_sfnt_off0000d2a5.bin
ebe9595c0d02871fa44dfee954b28f005906bb0630d1822bf7a1f91d227255f9
pdf-font-stream PDF embedded font (sfnt) at offset 0xD2A5 10620 bytes
font_02_sfnt_off0000ead5.bin
6b9f0e33e2a49179967efc903dad5057dba934d8ea3faf51c5fef6020180fde6
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD5 15616 bytes