Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b491651e76bb2a0…

MALICIOUS

PDF

79.0 KB Created: 2021-07-19 21:08:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 04b51d1d4828bff225b67a2ca6d0bafe SHA-1: 695912f02cd353ea34d274bafd922ca0611f3556 SHA-256: 2b491651e76bb2a0c3998a10678af6e33b975d63154829833ab454a8e5b4b91e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm. ClamAV and ML classifiers identified the file as malicious, specifically a phishing trojan. The embedded links are likely used to distribute further malicious content or to manipulate search engine rankings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://sacoorhealth.pt/site/upload/file/87269151633.pdf
    • http://yejida.com/userfiles/file/16916046930.pdf
    • https://burgas-remonti.com/userfiles/file/koralejivato.pdf
    • https://villatoscana-pi.it/userfiles/file/tojuvi.pdf
    • http://watthaistuttgart.de/userfiles/file/ginuxepexutarivuzakeb.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607d947a2b84d---88844252956.pdf
    • http://ducthoaudio.com/upload/files/zebazu.pdf
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9ac56c36f---50728643456.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076e400d3781---fofuzupikom.pdf
    • http://jirehenl.com/userfiles/file/042002422967.pdf
    • http://sunjewelsonline.com/userfiles/file/vatisojudizopa.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/da78e904ea2eae215fa73fbcfc6a1c7a/954923973.pdf
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/rr77r1q543mn32mp8cr4a176jr/20557728184.pdf
    • http://ledspectrumthai.com/ckfinder/userfiles/files/30498953581.pdf
    • https://communeouchamps.fr/userfiles/file/pefibafijutuxomewiniz.pdf
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae373589542---60795973257.pdf
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/eaf76082253877dea08cab583b036ebf/kixononozadawogozekez.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4534c0973e---13119515449.pdf
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/24887cc02401eb4e9da29cb9ad475dee/75264943365.pdf
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/49144849231.pdf
    • https://2ruoteexpo.it/ckfinder/userfiles/files/lifuzijanipefiv.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=the+elements+in+group+iva+of+the+periodic+table+all+have+electron+configurations+ending+in
    • 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_off0000cd24.bin
8eb7c00a6257179ed0ad711cca8682c44f2ba39c7ccebc73957486cbe91fb94c
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD24 11336 bytes
font_01_sfnt_off0000e73a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE73A 16792 bytes
font_02_sfnt_off0000ff4c.bin
2ab1a2a4f49cfd9f1ef4fd9ab1bf92c7c0f1a1ba9284a710bbe45d099062dc73
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF4C 16956 bytes