Malicious PDF — malware analysis report

Static analysis result for SHA-256 51bc8913b6f3e14d…

MALICIOUS

PDF

86.1 KB Created: 2021-06-28 06:08:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 34270ce0cf4d119d59bf3f60f65db708 SHA-1: ae8852273c6b1e5f07e1e70410583fd6a2d2264b SHA-256: 51bc8913b6f3e14d08931353a29d075926ac5b415799b9ccdaabc871c6d6d418
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of an attempt to lure users to external resources.

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://cavalier-hundezucht.ch/userfiles/file/59266767358.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/dcf6bb2ba02fbbd8941143bf2ac8f2b2/60709494707.pdf
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/d9abr9vmjldrmk6coedhmi4lvv/fexagukiviroxuzuw.pdf
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eac3680123---vaditex.pdf
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/e046ed5a868a890cf5283ab1b7fd4aa3/58287447285.pdf
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/16077596590839---terez.pdf
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bbd8699a637---mugulegiroreviti.pdf
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606da5557487c---fogezifuniseg.pdf
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16096a71501dbb---fosalujelezapanaguve.pdf
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac5895d0435---vupos.pdf
    • https://bluetact.com/ckfinder/userfiles/files/54482372675.pdf
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/6f6a255f8b7128d8b7dd2babad4bab47/84266272009.pdf
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/ec3671dcb96f67e9be16edbf51f9c8b8/53416255331.pdf
    • https://alllegaltask.com/wp-content/plugins/super-forms/uploads/php/files/k9h6hfduqe00ei0ifaje1ko4tf/vujip.pdf
    • http://manajrgvaaradhi.com/cms-uploads/files/4381221953.pdf
    • https://realestateconnect.pro/wp-content/plugins/super-forms/uploads/php/files/4idjg5ss15thb5becu3molmkh7/82326612835.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086d558a33e0---bisemobapixafetexe.pdf
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a3eecd39f34---zimekemif.pdf
    • https://amitadevnani.com/userfiles/file/18316899078.pdf
    • http://korvet-sp.ru/userfiles/file/ritogez.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a63a7124d13---89197737422.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=tim+berners+lee+on+the+internet
    • 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_off0000ee24.bin
f40f33c527cdb0140ebbe0024acd790322aafe820f81e8eda2b43472fe465916
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE24 17656 bytes
font_01_sfnt_off00011c58.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C58 16792 bytes
font_02_sfnt_off0001346f.bin
f5d0728e3418df4a6398253cded65120a76ee380e62393bd5e94ef61379fd652
pdf-font-stream PDF embedded font (sfnt) at offset 0x1346F 10316 bytes