Malicious PDF — malware analysis report

Static analysis result for SHA-256 42dd727912e611ec…

MALICIOUS

PDF

88.9 KB Created: 2021-08-20 13:16:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0f20803baeee267eb8285925a3d6270d SHA-1: b90acbc1004bd26353727f77a71b6e173f7a7b4c SHA-256: 42dd727912e611ecb2f939e580c01dbd4e36855d23d191064a7cc6a9f2a918ce
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, containing numerous embedded URLs that point to various websites. Several of these URLs are hosted on compromised CMS uploads or disposable domains, suggesting an intent to distribute malicious content or conduct phishing operations. The document body is heavily obfuscated and unreadable, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://rybczewice.pl/userfiles/file/98880737686.pdf In PDF document text
    • https://craftsmancuttingdies.com/wp-content/plugins/super-forms/uploads/php/files/08347d09ea24246d2d1663e87588415b/sefikoruza.pdfIn PDF document text
    • https://soudurelausiere.ca/upload/editor/file/rojatenez.pdfIn PDF document text
    • https://vinadesigndanang.vn/uploads/image/files/95492799364.pdfIn PDF document text
    • http://wxeina.com/userfiles/files/69916566778.pdfIn PDF document text
    • https://theloneranger.tv/clients/loneranger/ckfinder/userfiles/files/40879537237.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021052621423418.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/fcf6160e15e6b80c145451c24fcfae7f/kesirizolopofodibaweg.pdfIn PDF document text
    • http://bhttourist.com/upload/fckimagesfile/9027173167.pdfIn PDF document text
    • http://eotp.info/sites/default/files/fck/file/78510177671.pdfIn PDF document text
    • http://naucseto.cz/storage/37330538934.pdfIn PDF document text
    • https://hse.tw/upload/file/vekovutivetikirenavekemus.pdfIn PDF document text
    • https://weyergans-hcc.lv/userfiles/file/65425628465.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/ufkmthf7apgp99h4a7uq2q7oov/vapevofatoxurosovupek.pdfIn PDF document text
    • http://hondatayho.vn/images/ckeditor/files/roburekuto.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/8012507443.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/56599711421.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1609d55ccc0326---xewud.pdfIn PDF document text
    • http://biolabsrl.org/userfiles/files/80729699657.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/8054368c63354bfa8a1d7de6015e6643/31147079805.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bcb589db130---21183471334.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/160fed0fdda5b1---50065019310.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607af92398ed0---xujipivijibos.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/f500c1395120e84b60bb7b1a313cb7bf/6915079474.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=polytechnic+entrance+exam+syllabus+2020+group+aPDF 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_off0000f37f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF37F 17432 bytes
SHA-256: 4a0411c212bc782caea25be1f6dc696254af88de49442e465ee81c4301a637b4
font_01_sfnt_off00012100.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12100 11520 bytes
SHA-256: 0b79aee8460f13aa0298cd02fc0bfb17de253a2581f31a524bc26c5ba06e8ad1
font_02_sfnt_off00013c0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C0C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1