Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb33f0aea4a5e639…

MALICIOUS

PDF

73.3 KB Created: 2021-09-28 02:10:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bf8d7e33447559178f230bdf219bae65 SHA-1: 9bb4f48a92310618bcd40b264d8ef438541dd9cb SHA-256: bb33f0aea4a5e6396151f0e939271b8a408c23542c55b6b9effc281966dabcb9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The heuristics indicate that the document is part of a link farm hosted on compromised WordPress sites, likely intended to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, with the embedded JavaScript likely facilitating the download or execution of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e3c3eea77b---95731245533.pdf
    • http://piannocreativo.com/js/new/fckeditor/userfiles/file/34620519362.pdf
    • https://samowar.ch/upload/file/torexofomaxitubuzureke.pdf
    • https://office-agglo-larochelle.fr/userfiles/file/kerugamijevifokiruju.pdf
    • https://0922.sproname.com/files/userfiles/files/65170936895.pdf
    • https://alebusph.centralcms.cloud/galeria/files/20613650324.pdf
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e603d3d6f3---bifexesibufunipadiwur.pdf
    • https://itchanoi.vn/uploads/news_file/gozebowewimowudazo.pdf
    • http://chongqinghaohong.com/upload/files/69904715532.pdf
    • http://health-bridge.in/upload/file/50445071376.pdf
    • https://pnvvr.ro/userfiles/file/99390687229.pdf
    • https://lbjgold.in/ckfinder/userfiles/files/91006539293.pdf
    • http://fence-alarm.com/userfiles/files/litotil.pdf
    • https://kaptenhoki.net/contents/files/rifapewiweruzurolekurut.pdf
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/f02db029112ac573fe203574d0748320/xovukofometup.pdf
    • http://mcenterdk.ru/fck_editor_files/files/givujitezegofiwekone.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/718dc14b0bde36cbfe28038c08f6cf2c/69556345830.pdf
    • http://kelvista.lt/images/files/66393977933.pdf
    • http://babyindex.nl/images/uploads/jolepinufiluzu.pdf
    • http://lasermedia.cn/userfiles/file/xogate.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=video+to+mp3+pro+apk
    • 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_off0000b452.bin
689c6b4bf988da7cf5762e65f9b20d88fb9246a83b66d84f651d293cc20df90e
pdf-font-stream PDF embedded font (sfnt) at offset 0xB452 20148 bytes
font_01_sfnt_off0000e7ca.bin
50e95e7ce188c10e92d8749d951c7c379b7eb0b5bb556f4a7731aec12f5fb805
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7CA 10468 bytes
font_02_sfnt_off0000ff9c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9C 16792 bytes