Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81a91e7bd65f0ac…

MALICIOUS

PDF

77.9 KB Created: 2021-06-25 19:10:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 0a3944cac6ec9f715d4b6845896316d8 SHA-1: d38b308790b9af5f33fb79ad4743d4190aaa5bfd SHA-256: a81a91e7bd65f0ac469ee01869a05cce5c732a739cf3cc31ded94d5b8989913c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload directories, suggesting it's designed to host or redirect to malicious content. The presence of numerous external URIs and the nature of the detected heuristics strongly suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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 https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/9hnpi77g7oq87948vnm7monlba/lafozufurofo.pdf In PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/66pq4hl438n9phifhum3ddl6m1/lumodudo.pdfIn PDF document text
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/4bd65b507a7e2af63a9efd22f9e9697e/25898667103.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094da43686b7---ganisalevibexixatavok.pdfIn PDF document text
    • http://nedirajtebosnu.net/userfiles/file/30335994360.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/aagl2sf3mga35vokpggpt2i2g1/xepudidijuvemipe.pdfIn PDF document text
    • https://www.wflorlando.com/wp-content/plugins/super-forms/uploads/php/files/8b1c6e856d83d30ad13c562330910586/dawosupazinelo.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/16082cb5b97792---kotiritizomeruzumomitidi.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/topeduxazu.pdfIn PDF document text
    • http://beta-rc.com/upload/files/xigonaluzumila.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8a2d1d3076---ribabitamirevegaduru.pdfIn PDF document text
    • https://space1500.com/wp-content/plugins/super-forms/uploads/php/files/c66f53b6d63d7067f3f64e6091d777d8/15495006248.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160bacfbb284a9---xedodod.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/3753a542aa37fa4b9137e545e59437c6/6198407483.pdfIn PDF document text
    • http://lempreintedubois.fr/userfiles/lempreintedubois.fr/file/lowamodiku.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/8c52bd4c06174aa59fb758dd92634e73/89360215873.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b74028a51aa---49490906645.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/82df401e5b94d332c2c75534a96c67bb/vabaruwezixesoxigatuxom.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d266440618e---xotovovumafoxani.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/621f74a9f9316e035d3bc9bf948055c0/sarazokisilanurunuse.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4183e18c2---24566934171.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160afa74abf9f2---pokixonavosepujiba.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dcca3a9526---pobesojalajevipetikewid.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c893d262446---xefefomebisomumomu.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/87703802566.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=wowhead+essence+of+waterPDF 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_off0000cfae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFAE 16328 bytes
SHA-256: 0022892e6264b2f60ab30a17d6d0580a230368f699b20bf45aa9f9eff975b6db
font_01_sfnt_off0000fa22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011239.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11239 10512 bytes
SHA-256: ae28b3162752a3105247ea764556f0c6ac3b4b317dc51fd7a95cd9d401be30e0