Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1ef29ffb9e83271…

MALICIOUS

PDF

73.4 KB Created: 2021-09-20 17:03:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4deb8803571d94831a13e7e162b88773 SHA-1: 700ee0dc094378431581f8c1f8377ed4790437c4 SHA-256: a1ef29ffb9e83271748400b1e1b83ac7ce74ccb7e6540232ac9fe52ddfdfd014
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. The presence of multiple external URIs and link farms suggests the primary purpose is to redirect users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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://ketchas.ru/uplcv?utm_term=downfall+streaming+free PDF link annotation
    • https://jokerprod.net/userfiles/file/22934684176.pdfIn PDF document text
    • http://sperrincaravans.com/images/file/18142548887.pdfIn PDF document text
    • http://kool-house.com/upload/editor/file/86873797974.pdfIn PDF document text
    • http://neboskreb-irk.ru/uploads/userfiles/files/12910907906.pdfIn PDF document text
    • https://xn--fct8ml6mwue.tw/uploads/files/3880200134.pdfIn PDF document text
    • http://samnakthodrahassob.com/userfiles/file/18819284684.pdfIn PDF document text
    • http://muzeumostrowiec.pl/obrazy/file/23100134946.pdfIn PDF document text
    • http://world-housing.jp/ckfinder/userfiles/files/vezujobujetufipasozobetew.pdfIn PDF document text
    • http://booklandbooks.com/userfiles/file/21782522713.pdfIn PDF document text
    • http://behtarinekhodetbash.com/files/files/zipumag.pdfIn PDF document text
    • https://eventaipei.com/upload/files/79980451450.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fce2130999---93673684971.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/161430a8bc73a5---5706976090.pdfIn PDF document text
    • https://www.wizzfizz.com.au/application/third_party/ckfinder/userfiles/files/17727329140.pdfIn PDF document text
    • http://sunwisechem.com/Uploadfiles/files/wazilikotowovezovuwebe.pdfIn PDF document text
    • http://www.farmaciapenil.es/userfiles/files/2259485443.pdfIn PDF document text
    • https://shibbirs.com/media/files/9549700535.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/72201167705.pdfIn PDF document text
    • https://moderator.lt/components/com_mijoshop/opencart/image/data/files/pibuximodagiwogurulalimuf.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16130b37a7f0f9---tomot.pdfIn PDF document text
    • http://gpkoaee.ru/ckfinder/userfiles/files/51676975168.pdfIn PDF document text
    • https://junona.manyel.website/images/uploads/medium/pumomagikekexinijo.pdfIn PDF document text
    • http://laulumaja.fi/ckfinder/userfiles/files/panozosepixekelasaze.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139ab65cdeb4---fipofonazifawetarogos.pdfIn PDF document text
    • http://ailizia.com/userfiles/61266526286.pdfIn PDF document text
    • 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_off0000bc63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC63 10644 bytes
SHA-256: 17bbe4750d32b6609fc45b7a9f236dc68e2468b0be39b608940534917cc7b5c1
font_01_sfnt_off0000d4d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4D1 16888 bytes
SHA-256: acf3206380ab92413cb5e6b0fa27615c95e043643280d522f64b5be0c376f381
font_02_sfnt_off00010074.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10074 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1