Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5c436e34e55b0bf…

MALICIOUS

PDF

69.4 KB Created: 2021-09-07 01:11:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 03fc170e27748bfa384e1ea11916a1a2 SHA-1: df423082fa66bc823fd17f1fe12d1ba3602a605b SHA-256: a5c436e34e55b0bf117e8199b42307a1b81b7c8ac5715eb6c2543eb1c900aa3d
156 Risk Score

Malware Insights

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

The file is a PDF that contains a link farm, with many URLs pointing to compromised WordPress sites. These links are presented in a way that suggests they are search results for a specific book, likely to trick users into downloading further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/vilfe5skgivsm93ctb5ra61dn1/91716775376.pdf In PDF document text
    • http://timnhanhonline.net/upload/files/10193866769.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/a8244861edc134cb38717d5a0f38c36f/79583331301.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16092648d2edf0---9046282828.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1611453e418613---repiwediza.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0348355585---rekemevusito.pdfIn PDF document text
    • http://wonsakai.com/uploads/files/94034883675.pdfIn PDF document text
    • https://infypos.com/infyposcms/media/zeguluxe.pdfIn PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/24023478377.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///pekisedapuriwupibidu.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/16123a03eb2360---nalifenuzokew.pdfIn PDF document text
    • https://travelstore.tn/userfiles/file/lesisaj.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607c84363b777---66529138300.pdfIn PDF document text
    • http://novussiteyonetimi.com/uploads/file/xemazojiwa.pdfIn PDF document text
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/1bb2ceb636ce5a570abfc90e0e79a618/kelemowonebesaduxume.pdfIn PDF document text
    • http://hizirferforje.com/admin/fckeditor/editor/images/file/xabafevefuzekefisirorow.pdfIn PDF document text
    • http://doyen.cc/images/upload/File/81045067335.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/4b2d72425e93a26bace173ad458025af/winutejer.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160c77c5acc8da---tudukezijofoguj.pdfIn PDF document text
    • http://goref.ru/files/file/bepelugimolaxex.pdfIn PDF document text
    • http://dichvu12h.net/userfiles/file/zitumemuzidipapuvej.pdfIn PDF document text
    • http://atomleasing.ru/media/File/fewexuma.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=fakira+marathi+kadambari+pdf+free+downloadPDF 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_off0000b13c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB13C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c953.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC953 10888 bytes
SHA-256: de890293fe95fd487e1d52c604e32068129f4460a844b60bcf73d7cf90c261aa
font_02_sfnt_off0000e20f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE20F 14852 bytes
SHA-256: 2b4f0b569c9f202df70ca5c017c93fe606c7fe0870acc0d082a73739287549da