Malicious PDF — malware analysis report

Static analysis result for SHA-256 83f6ef7cfaf41edf…

MALICIOUS

PDF

87.9 KB Created: 2021-07-13 13:01:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: 51b3cfdbfb33184cb91ad41a686888b4 SHA-1: e6401e33827c777cc64b9a7f90fff79eddd4347f SHA-256: 83f6ef7cfaf41edfd51bc6f98a9292f1d245992beb2ca6a8833a417cecae5c99
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to compromised WordPress sites, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to lure users to malicious content or phishing sites. The presence of multiple external URIs and link farm heuristics supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086fcd13e608---71040601423.pdf In PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/cmpigt24njdqmj1rkdertfsln9/97525614216.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/b239ddbde8ec342042f9454f2bb4ec66/pufepimeliwevomivixo.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0e1acd66f8---8333169500.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/9abded73399815a423505af3194156b9/nejuwatabogepotewisikuj.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/51bb8adec9c5de573594bf8501b52152/gerakig.pdfIn PDF document text
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/707961d33124d4b24d5b1f39a824c0bc/sedudax.pdfIn PDF document text
    • http://www.asslar.de/downloads/24834244622.pdfIn PDF document text
    • http://industrialdevices.in/uploads/pajasefis.pdfIn PDF document text
    • https://nada70.org/userfiles/file/37098399984.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/7b253d600471fc04085957460bbd507a/488049153.pdfIn PDF document text
    • http://inter-travel.hu/_user/file/60087301073.pdfIn PDF document text
    • http://franklcalabreseattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/ximipirukujagu.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/46qk1vqh6gatlojjbaphr65ub4/28436422297.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609836e64348c---supekowodamuzezib.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/c1a6aa808364746c3acebd9f3424e18f/70257838404.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/fd72c78d2f53e23b246a1bbe91558973/suripafupos.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/6454471ed2533a4696571cd6d1a2863a/batokuwo.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/160bc80ec650c3---80571213531.pdfIn PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a0f4e65d9c6---supugobopefovokemi.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f1326d2a7c---82845281236.pdfIn PDF document text
    • http://falerisztika.hu/tmp/9440961725.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__60B982346D072.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160add29eaffed---47548143088.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/efb145cb65912e347d548bb6a21643be/pavixiwekez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=harry+and+ginny+fanfiction+after+the+warPDF 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_off0000f2e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010afb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AFB 18068 bytes
SHA-256: 7c865c5ac6b49527b7bac6d368065117cebfb4d2c279354c97d14dd217d155d1
font_02_sfnt_off000139af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139AF 10732 bytes
SHA-256: cc9b51b313bb4f06e3662edc26a14749767c36aa810f9e197d3a9d374ab39a1d