Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81c70d88e386b16…

MALICIOUS

PDF

72.1 KB Created: 2021-09-06 22:32:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 1387ab177a68274c31b201750aa8f5da SHA-1: c51a43057eaf5f6f8cd84b3b22436c5abc237549 SHA-256: a81c70d88e386b165c1848efd8ceef1e295bff2ddfbb180e919b26050b3abf61
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by ClamAV and exhibits characteristics of a PDF link farm. It contains numerous embedded URLs pointing to other PDF files hosted on various domains, some of which are associated with compromised CMS uploads. This suggests the document is designed to lure users into downloading further malicious content or visiting phishing sites.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.3653

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://digireg.org/upload/60710608987.pdf In PDF document text
    • http://tevukasveza.lt/ckfinder/userfiles/files/vadivolezarumari.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/kexizuf.pdfIn PDF document text
    • http://limoride.net/gallery/file/51959641310.pdfIn PDF document text
    • http://atlonnuri.org/UpLoadImage/editer/files/xezopeniwawovexeraro.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a41d7a179ff---mogumejovibinatukelo.pdfIn PDF document text
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/16070701a4525d---xemomiseb.pdfIn PDF document text
    • https://hamzsabegi60szallo.hu/UserFiles/File/lekidujubexenevo.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16101136e54ad6---845991638.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/82254887443.pdfIn PDF document text
    • https://swagath.co/new/ckfinder/userfiles/files/dilubixof.pdfIn PDF document text
    • https://avonsteel.com/UserFiles/file/mobojivowavovifipox.pdfIn PDF document text
    • https://aglogistics-bo.net/userfiles/file/19973742490.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/6j72uepbp79rcmlrp3dd8u6t5s/85409101423.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/71199602550.pdfIn PDF document text
    • https://soalmatematik.com/userfiles/file/69938598099.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/169804e5b9cb5ea6f8485787b5f34999/14394056391.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ab837b1777---zepikejajiweka.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/lamaxejefosewogizorelizuk.pdfIn PDF document text
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/ik8addjrh5r9dqd095c62mi9s5/46768176682.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160855e595697f---44613033238.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/togasolezizumaviwob.pdfIn PDF document text
    • https://bloomland.com/sites/bloomland.com/files/50891836683.pdfIn PDF document text
    • https://nstoplana.rs/ckfinder/userfiles/files/70829394712.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=tramex+skipper+plus+manualPDF link annotation
    • 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_off0000c034.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC034 17288 bytes
SHA-256: c4254ec257696f7f629d52ebb28e22799559bc72a248895778970614709a736d
font_01_sfnt_off0000eca3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104BA 10452 bytes
SHA-256: 3dddf1a0ca193ab8ebd36ed2c355d97c81671ce8ce2825ca139e3a77cc3a54e6