Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca35c561b6a2b4ee…

MALICIOUS

PDF

77.5 KB Created: 2021-07-03 03:11:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: f3ab19d336ecb07e0f7e39cc5df753c5 SHA-1: a3d759a472ef95eb912613eb136749cbc60d9127 SHA-256: ca35c561b6a2b4ee569e74717440cd0790b43df08a37de14f8217588ebab8d3d
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress upload directories, suggesting an attempt to distribute malicious files. The presence of a 'utm_term' parameter in one URL indicates a potential phishing or spam campaign aimed at tricking users into downloading software. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://coretry.ru/uplcv?utm_term=mp3+video+converter+apk+free+download PDF link annotation
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4840e75721---59643797649.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/61268456973.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160812e2ae03ab---29312518654.pdfIn PDF document text
    • http://lucann.com/Upload/file/73559959148.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f0e4bd1499---19996227981.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160981dfd6920a---soximekijebagiw.pdfIn PDF document text
    • http://elazentrale.de/images/uploaded/file/judasuwozitige.pdfIn PDF document text
    • https://chameleoncoupons.com/adgprocessing/uploads/files/35160638122.pdfIn PDF document text
    • https://unosms.us/userfiles/file/fukix.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/gowerisexawekusopite.pdfIn PDF document text
    • https://glycocalyx.nl/userfiles/image/file/99734512172.pdfIn PDF document text
    • https://smartcirclegroup.com/userfiles/file/98525256063.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/tovorilomuf.pdfIn PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f453cdb051---10380717337.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/25366822423.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/kufosazemixilekekumezusi.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/26056435735.pdfIn PDF document text
    • https://www.nrlandscapes.co.uk/wp-content/plugins/super-forms/uploads/php/files/d5d5ba27d32d17c8fe75477c59778ede/40789558807.pdfIn PDF document text
    • http://rogo-rotterdam.nl/files/rerejali.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/cb2b93e2700904f596792a1729fe3fd6/muxipirazadusexelebutuda.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607cfa279a37d---65685764405.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/dusorojulikenaduminujaros.pdfIn PDF document text
    • http://studiopetrilli.it/userfiles/files/82898396883.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160904f0e1eb6b---28935929756.pdfIn PDF document text
    • http://fd-health.com/upload/ckeditor/files/47214480330.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_off0000cae6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAE6 17100 bytes
SHA-256: 2223e21f9fad4846d2b5f5f7f85b8a12db4c710ae3ca6acf253344a2d9e75986
font_01_sfnt_off0000f720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF720 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F37 10852 bytes
SHA-256: 8f175d8266bde29aef81773beb40f99e7bbe49c5bd88aa67fa400385b8e873aa