Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8c83fc9380c7bfe…

MALICIOUS

PDF

81.1 KB Created: 2021-09-07 05:59:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ba3f411b2983da47e7611be70b3f8ea2 SHA-1: 9962998a2cffcd51895b9a19e000c2fe7b43d280 SHA-256: f8c83fc9380c7bfe25b3ebc6990010ee8d130bccc9dd65d920f66a98a6015ceb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document is classified as malicious by ML models and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to various external URLs under the guise of providing JLPT N5 sample questions. The presence of multiple compromised CMS upload links and disposable hosting suggests an attempt to obscure the true malicious destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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 https://salvatoredivilio.it/userfiles/file/xoxugozavezulusabasabefup.pdf In PDF document text
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/28be3c61b7baa4fdc9c4f16988c3a767/23136211757.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/mozepejusimi.pdfIn PDF document text
    • https://beldaoyun.com/calisma2/files/uploads/xekije.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/43527804063.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/ulqu8u8aht7vjpmlbic9jrmqc6/91769583990.pdfIn PDF document text
    • https://panegovernance.com/ourprojects/chowki/UserFiles/file/rogujajuril.pdfIn PDF document text
    • http://client.diffuse.info/files/muzapavidelafivifudu.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c925119ad8---xofapenaduwode.pdfIn PDF document text
    • https://veterinarycarefoundation.org/userfiles/file/rapaluja.pdfIn PDF document text
    • http://studioturina.com/userfiles/files/butenef.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/a42cc457843c83e13bccb01b3283f9bb/42375742999.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/161261744a06b6---59960068028.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/ca6054e2ef724bc394b9a4b3ac68d3d6/zejuxujifenopi.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/v8mp23lr39vjaq9emv8jboflj7/83902193948.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/17882650385.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/71265460297.pdfIn PDF document text
    • http://bhttourist.com/upload/fckimagesfile/guxekoledoxo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=jlpt+n5+sample+questions+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d322.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD322 19476 bytes
SHA-256: 59476be952d6b54c66f129a6669f2a32a52ec3cd5ac2597451eb562d334953e9
font_01_sfnt_off00010608.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10608 10932 bytes
SHA-256: 4b9a25e0901b575da2f9db1c04b6f270960e688e6492432865be0a0cd1df6285
font_02_sfnt_off00011f2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F2D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1