Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b03120b056953c6…

MALICIOUS

PDF

73.5 KB Created: 2021-09-17 18:58:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4f7be6e6a4a596486fc42a360d74457 SHA-1: 553a4bfa592018d95bfb1f701f8ad1d6339f4cee SHA-256: 4b03120b056953c6c7449fbdb0c218b26e4fc6cb8523d0a31d1d6d421a909850
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links pointing to compromised websites, identified by heuristics as a link farm on disposable hosting. ClamAV and an ML classifier flagged this file as malicious, specifically as a phishing trojan. The presence of these links suggests an attempt to redirect the user to malicious content, likely for credential harvesting or further malware delivery.

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://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613202cc811a3---69106899971.pdf
    • http://ingmontagna.com/userfiles/files/77985004127.pdf
    • http://fijiembajak.com/uploads/ck_uploads/files/bunerigaduxenav.pdf
    • https://tectrongim.com/uploads/files/37069777601.pdf
    • https://ikincielinmak.com/upload/ckfinder/files/furipulavupotuxaxuzux.pdf
    • https://soccerauquebec.com/userfiles/file/besegigezamop.pdf
    • http://eltprof.ru/userfiles/file/11821623414.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612f61cd2c367---34616366725.pdf
    • http://kehlux.lu/userfiles/files/33461373981.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140a87363425---32095061112.pdf
    • http://denis-lefebvre-services.com/fichiers/file/pabonekawu.pdf
    • https://www.sonorisation-auxerre.fr/ckfinder/userfiles/files/97320844592.pdf
    • http://dotbamboo.com/file_media/file_image/file/71717690238.pdf
    • http://xn--jt2b56wn0ap2a.com/upload/file/202109140948411291.pdf
    • http://4rrecycle.com/files/file/76025367844.pdf
    • http://pro-group.ru/userfiles/file/dufidawiluper.pdf
    • http://fueandhair.com/userfiles/files/73367866223.pdf
    • http://zzps.pl/userfiles/file/72466326061.pdf
    • https://theipbuzz.com/images/file/gukezamilemujilodazin.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/161346a46a2768---jikexidetu.pdf
    • http://baove247.org/upload/files/digalal.pdf
    • https://dpt-mh.com/uploads/news/files/61010155368.pdf
    • https://mmoxx.mn/userfiles/files/xufowa.pdf
    • http://fruitvita.com/files/files/74771621192.pdf
    • https://shieldtech.cz/ckfinder/userfiles/files/sagipavopemumasid.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=animation+in+recyclerview+android
    • 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_off0000bcc5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBCC5 16792 bytes
font_01_sfnt_off0000d4dc.bin
06fa7c43f662b26608396454d5dec2f8e290ce1b7a7e348d905c6bfa423a537a
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4DC 10608 bytes
font_02_sfnt_off0000ed22.bin
9770e6e557a566106d5e46279f8cfe0c2839106372747ea255c6cc8106da3054
pdf-font-stream PDF embedded font (sfnt) at offset 0xED22 16376 bytes