Malicious PDF — malware analysis report

Static analysis result for SHA-256 83249bd66ef2cc81…

MALICIOUS

PDF

87.4 KB Created: 2021-06-25 21:52:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 9a6019d8560ad79c167475082a498a3c SHA-1: 1ef4201f1191be2309adbcb96753eb16d0dd37ed SHA-256: 83249bd66ef2cc81b0b71ee88fb218048b0e0b6e10f04ba4e74236aab0c7e502
96 Risk Score

Malware Insights

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

The PDF contains a link farm, with many URLs pointing to compromised CMS upload directories. The ML classifier strongly indicated maliciousness, and the presence of numerous links on disposable hosting suggests an attempt to distribute malicious content or redirect users to phishing sites. No scripts were extracted, but the structure itself is indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 5

  • 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://auf.vn/wp-content/plugins/super-forms/uploads/php/files/sp9ud2f87sbi1db1fs7qqvtdj7/97351753797.pdf In PDF document text
    • https://btegypt.comfile/96955792557.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084c63090e40---80212922925.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/buneri.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160adee4ec2ac3---rudemutowodet.pdfIn PDF document text
    • http://bobiniauto.com/userfiles/file/90187960706.pdfIn PDF document text
    • http://ithaca1962.com/clients/41687/File/tilunipiwikuz.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c11a5649f53---tipav.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b72e971873a---nibivudetulovugolamav.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/36e2e663162558d082c87eecd943cc8a/batufinux.pdfIn PDF document text
    • http://jgbt.us/pds/userfiles/files/34864277107.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/a84ae2a2rmfaisl9tfq3bj1m4n/94412002669.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/5cc30ff8776523c65d81e855b87bb4c6/pawetedu.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160874ea91f5b5---93219862052.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/hdgfjg0m1qupteal84564n3jat/tenekapuvadimudamotavovu.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607113a5d5aec---duvadofesotudor.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aeb41427563---sodolafowa.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1607e6b5c79f94---porukitawegubemoruwupope.pdfIn PDF document text
    • https://aneri12.eu/res/file/jurixavorin.pdfIn PDF document text
    • https://eatorhours.org/e-bussiness/fckimages/file/90838613197.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/99128149506.pdfIn PDF document text
    • https://heritagecambodiatravel.com/userfiles/file/40820991853.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0dc61d618e---mugukidibukorovixitiga.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=primordial+soup+theoryPDF 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_off0000f201.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF201 18064 bytes
SHA-256: a619c053a2088c144875db7f4e39ce3ea0099496762fc309bb9b24a945146923
font_01_sfnt_off00011fb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000137c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137C8 10768 bytes
SHA-256: eaeb9a13cd78d3f0dc899fb19589fc10a16b3849423c96968f8bc6e465dd1746