Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc661c0a0c265e07…

MALICIOUS

PDF

68.8 KB Created: 2021-09-26 14:14:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0a5ae9dee440aee8f89c6daaee77bc43 SHA-1: d2f930f2571491c5f32dde74acac18cf202e652c SHA-256: bc661c0a0c265e0760add4ef96688b0dba81ffc4cd0263a0d52c02a2653fd5b6
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://wastran.ru/uplcv?utm_term=android+sync+contacts+to+new+phone
    • http://www.trackls.com/application/ckeditor/ckfinder/userfiles/files/xikakokopewibete.pdf
    • http://ayurveda-shiatsu-qigong-nice.com/upload/files/12748769301.pdf
    • http://klm-co.ru/foto/ck/files/50024653753.pdf
    • http://domario.ru/userfiles/file/71416810400.pdf
    • https://residenciasanamaro.es/userfiles/files/kipaloruzonurota.pdf
    • https://dichocungtoi.com/userfiles/file/zoralalapitibegefuvagot.pdf
    • http://abwessex.com/uploads/files/77922746583.pdf
    • https://lawrenceyezersky.com/userfiles/file/8235440883.pdf
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16145aed83a1ac---40063761108.pdf
    • https://mccartha-cobb.com/userfiles/files/xutogatovuvigosumikolu.pdf
    • http://c2r.su/uploadfiles/file/2021091517201073499.pdf
    • http://lnshiyue.com/userfiles/file/20210908215557_347787326.pdf
    • http://nensi.si/upload/file/samave.pdf
    • https://sproname.com/files/userfiles/files/fojekake.pdf
    • http://e-park.es/img/uploads/files/2928892396.pdf
    • http://bbfrontedelmare.com/userfiles/files/21491967151.pdf
    • https://sunarchegypt.com/userfiles/file/jebofazefesorarutavix.pdf
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16137158a2f9cd---44748007733.pdf
    • http://yeditepegumruk.com/userfiles/kekukigosexavafi.pdf
    • http://franceplus.fr/userfiles/file/35614256761.pdf
    • http://local-minicab.com/survey/userfiles/files/zumovov.pdf
    • https://artlabjo.com/userfiles/file/juwenanosumugenijef.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16140e72c8ddf0---zijigudifojidinixofadesep.pdf
    • http://margheritango.it/userfiles/file/13582235883.pdf
    • https://evabizz.com/userfiles/file/loxikagapusojibujobafobax.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_off0000b07f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB07F 16792 bytes
font_01_sfnt_off0000c891.bin
5ab94190228008cc78a14eb9c12e8d8f8fad5d032d62b0df52b64b6e0b0eca41
pdf-font-stream PDF embedded font (sfnt) at offset 0xC891 14532 bytes
font_02_sfnt_off0000eca9.bin
deaaa8f7e29a8fac5c2bfb9df8d58d13c56497bc211353deb61f32f291a29b6e
pdf-font-stream PDF embedded font (sfnt) at offset 0xECA9 10744 bytes