Malicious PDF — malware analysis report

Static analysis result for SHA-256 9533c813eff3e931…

MALICIOUS

PDF

78.9 KB Created: 2021-09-01 08:33:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: daf8cd346c89a65db97657d747eb1b2b SHA-1: 8cd5451c29f7e3d5b2659f7be08aed685756b90f SHA-256: 9533c813eff3e931165daa0e7ea591be9c0480a2dc4a769bf31b18487da1ea30
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm on compromised CMS uploads. The document body is heavily obfuscated, but the presence of numerous URLs, many pointing to PDF files on various domains, suggests a phishing or malware distribution attempt. The use of 'utm_term=cad+to+pdf+converter+free' in one URL indicates a lure related to file conversion services.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://allycatering.com/userfiles/gonupafumosuzulode.pdf
    • http://riph.pl/userfiles/file/68882518876.pdf
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc802d0ee4---55547962099.pdf
    • https://www.esicm-old.org/admin/lib/ckfinder/userfiles/files/57421767211.pdf
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afbc60a330f---4338302800.pdf
    • https://eastmanllc.com/ckfinder/userfiles/files/digizeposexoguvajasaj.pdf
    • http://cck-brno.cz/ckfinder/userfiles/files/kitewumaluwaje.pdf
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf13378c63e---62859177146.pdf
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/0da9b9d86d7afcf9c0395526b892a5a2/raxotawedafiperipif.pdf
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612a957d525ce---gifixowol.pdf
    • https://vinasimex.com/uploads/file/57995964730.pdf
    • https://bibonatura.com/ckfinder/userfiles/files/balotuzanafadoru.pdf
    • https://cochleartudaskozpont.hu/files/11520622372.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/dda712992c18ca1ad5af4a5f96979271/gozed.pdf
    • https://ksboutlet.com/file/files/3852553517.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160806ea718c5b---64088563780.pdf
    • http://www.tomasjelinek.com/img/pub/file/supuxeripuzupurivoligon.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16074215fa2e85---81927522554.pdf
    • http://jarosi.hu/files/file/65385863245.pdf
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfc00a5741---remegadametaruxisew.pdf
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c51d014d9d7---39987248163.pdf
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/qef1gdupdrgfefi9ev1p1obr42/75766017097.pdf
    • http://coreaad.com/DreamDataUpload/file/81291661520.pdf
    • http://uzks.hr/upload/datoteke/86635003922.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=cad+to+pdf+converter+free
    • 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_off0000d374.bin
98a16751d16ec6b77b0266e17aa0f0e1ad9bd5afef796336b55a8385b6578887
pdf-font-stream PDF embedded font (sfnt) at offset 0xD374 10404 bytes
font_01_sfnt_off0000eb28.bin
5cb718955ba45d397666a3580941a8a5394e2ad31e760dde0509fc6450744d76
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB28 16160 bytes
font_02_sfnt_off00011492.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11492 16792 bytes