Malicious PDF — malware analysis report

Static analysis result for SHA-256 81dfe3d4cde10b26…

MALICIOUS

PDF

73.7 KB Created: 2021-09-09 19:46:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: a62f0bf5f6a42f71f5d911e43d87e27b SHA-1: 2148269580947dd08b96f0631cd0441554bb9360 SHA-256: 81dfe3d4cde10b260ff1ccfd885c5ab762d92fd4cd3711216f4e3c1fba8a03e0
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm on disposable hosting, with multiple URLs pointing to compromised CMS upload storage and other unknown domains. The embedded URLs suggest an attempt to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://estoniapools.com/contents/files/bakusosowomivefasuvedamiv.pdf In PDF document text
    • http://eldorautomaticgates.com/UserFiles/file/21545056364.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/luguzotivivivarisig.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613331fdc73b0---dapatodukivu.pdfIn PDF document text
    • http://stoka-saarlouis.de/userfiles/file/37733723397.pdfIn PDF document text
    • http://cornaredo.gattinonimondodivacanze.it/themes/userfiles/files/52944563256.pdfIn PDF document text
    • http://fullx.net/files/13917969198.pdfIn PDF document text
    • https://larioenergy.net/uploads/file/wakenunixukurukebu.pdfIn PDF document text
    • http://goldmustang.ru/files/files/6971969608.pdfIn PDF document text
    • http://baloneacessorios.com/_upload/file///sabikozezazarevenulo.pdfIn PDF document text
    • http://zagazzo.com/userfiles/file/xuzagix.pdfIn PDF document text
    • http://avtosfera28.ru/userfiles/file/kelejedopeserememabewuj.pdfIn PDF document text
    • http://ulv-fogger.ru/d/files/56151798195.pdfIn PDF document text
    • https://askisan.com/upload/ckfinder/files/5655816085.pdfIn PDF document text
    • https://tootooair.com/FileData/ckfinder/files/20210909_F3F3278CEC86F48C.pdfIn PDF document text
    • http://tingchucontrol.com/Uploadfiles/files/2632434004.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134f4812275b---jufovisorarepinixaw.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/12bac1ab7e84297b433cecec4d22772c/75246012221.pdfIn PDF document text
    • https://eghamatsafar.ir/basefile/eghamatsafar/files/78234019647.pdfIn PDF document text
    • http://thesciencenetwork.org/uploads/files/53434918278.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136062165ecb---nopepebu.pdfIn PDF document text
    • https://svarovanijelinek.cz/ckfinder/userfiles/files/57238404845.pdfIn PDF document text
    • http://maekalocal.com/Maeka/UserFiles/File/45423677709.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=assasin+creed+rebellion+apkPDF 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_off0000bd3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD3D 10624 bytes
SHA-256: 1061e12b33ad7e76161f30f0f11126cbed8d9500a3659fa44de43b1505da8d35
font_01_sfnt_off0000d55c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD55C 17400 bytes
SHA-256: a3f7b82657c668d3d53ef43179623ec79fed8a3a9af071a265d4917b7fb1285e
font_02_sfnt_off0001013b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1013B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1