Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5ffdca733e3129c…

MALICIOUS

PDF

84.7 KB Created: 2021-09-05 23:07:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5cb17cb05f3d9660452b9cf80c50865e SHA-1: 7d9fb09406decb8f596a6f86049ade0699a24487 SHA-256: c5ffdca733e3129c7e88a263c5eef5b3a093102f2551f61a7697c6828c8fa564
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/vetlnju98veapg2otmmusf8mo5/jojapiluxixemaku.pdf
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/aa92292bd402aff372c69a7aec89331f/217915141.pdf
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607f40e2a054b---42690437928.pdf
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160be1c57ec972---89900822635.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b0c5c308977---71570985360.pdf
    • http://capableapp.com/uploads/files/zuvuvafidisefaxot.pdf
    • https://davaocarrental.com/images/file/rejara.pdf
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087e5485472f---xonubam.pdf
    • https://dianthusindustrial.com/resimler/files/dirozipigumilipetag.pdf
    • http://texmet.pl/userimages/file/9672170247.pdf
    • http://trhs64.com/clients/c/cf/cfad56e582d93fa9eda51f2516e23bdb/File/vowiwazoboj.pdf
    • https://xn--fct5g39pjpo.tw/upload/leakstop/files/82381014766.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161062ea52c720---76771580384.pdf
    • http://bellina.pl/userfiles/file/dulutazinogam.pdf
    • http://zhizhencn.com/filespath/files/20210823015831.pdf
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a3c50eb2fb---kalopa.pdf
    • http://capitolmetrophysicaltherapy.com/userfiles/file/37499256149.pdf
    • http://zatacorp.com/upload/files/lonovuketageluw.pdf
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/j3oc7fmdm685dc8e4fsmka0boh/rikavemox.pdf
    • http://1night2day.com/ckupload/files/jikabixafunofera.pdf
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/8e7e351436edef11a0634c461e322607/16412949213.pdf
    • https://augsburger-dartliga.de/uploads/file/51203015856.pdf
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160d2685e47622---18537808171.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=lean+in+15+vegetarian+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e52b.bin
dca1ba47ff0473807972adc0946cfdbd039429ee928057f61287181cffe67295
pdf-font-stream PDF embedded font (sfnt) at offset 0xE52B 18532 bytes
font_01_sfnt_off0001158a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1158A 16792 bytes
font_02_sfnt_off00012da1.bin
a6722803da24ee96bdbeba816c56998ac902c5dae904d4735bee938c7d146a95
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DA1 10548 bytes