Malicious PDF — malware analysis report

Static analysis result for SHA-256 db3f018c4d5d3f31…

MALICIOUS

PDF

74.2 KB Created: 2021-10-02 18:12:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 99aa6255d27c8d6dba85cf63e1d95d4d SHA-1: f0209212dad6323315d657d581b2aa16eb363988 SHA-256: db3f018c4d5d3f311d85aea8cf7c0910c110dccc2153f06a0692d0e377cee46b
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to compromised or disposable hosting, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to malicious sites. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

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://serpavenger.com/ckfinder/userfiles/files/766374284.pdf In PDF document text
    • http://zlzljc.com/uploadfile/file///2021093019525952.pdfIn PDF document text
    • https://rumahbaruku.com/contents/files/90511821107.pdfIn PDF document text
    • http://tndgdemo2.com/ckfinder/userfiles/files/60519947418.pdfIn PDF document text
    • http://ratchadatitan.com/UserFiles/File/veragugo.pdfIn PDF document text
    • https://dycmc.com/DATA/upload/files/202109030934483381.pdfIn PDF document text
    • http://tuanayapim.com/rsm/files/95736291644.pdfIn PDF document text
    • http://xn----7sbbgprpk7biiq.xn--p1ai/admin/ckfinder/userfiles/files/96215095520.pdfIn PDF document text
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/t133ks04trffqsu1sam56js6qg/72214099690.pdfIn PDF document text
    • https://karlschool.org/uploads/files/202109080032381650.pdfIn PDF document text
    • http://revucue.com/ckfinder/userfiles/files/53742641564.pdfIn PDF document text
    • http://kientrucsangtrong.com/plus/files/zolezasukevobamifazome.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/be6jfeba57lgmvpdeme2ppk9vv/61526199182.pdfIn PDF document text
    • https://hideab.se/tc/Mediagalleri/file/82117580451.pdfIn PDF document text
    • http://yourtruck.be/upload/ckeditor/file/larexobozabizejezefa.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/e9b040856188e8dc278bb5e4c41f675b/vaxepasapisetavagarifa.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16147b6242a6fc---63728517496.pdfIn PDF document text
    • http://myucpb.com/userfiles/file/46070961627.pdfIn PDF document text
    • https://groupekineconcept.com/userfiles/file/66533937243.pdfIn PDF document text
    • http://scbczy.cn/up_files/file/20210928_111016.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/87292851669.pdfIn PDF document text
    • http://worldwidestationeryholdings.com/files/file/75355298802.pdfIn PDF document text
    • https://gabconstruction.com/ckfinder/userfiles/files/wubafamewojaxo.pdfIn PDF document text
    • https://stiglic.sk/userfiles/file/79808837566.pdfIn PDF document text
    • http://smart-ventures.ch/upload/Editor_Images/files/97680315241.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=1000+little+things+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_off0000b809.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB809 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d020.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD020 10940 bytes
SHA-256: ab5f63d3f233083abbd382712251cd7432296165b5b2c647749e8c639aca912d
font_02_sfnt_off0000e93e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE93E 19048 bytes
SHA-256: a97df311f2bb1b37d6ba4f62f3a8af25142ada2599944ed5ae3a28143cf26c01