Malicious PDF — malware analysis report

Static analysis result for SHA-256 28275496d8639708…

MALICIOUS

PDF

97.7 KB Created: 2021-07-05 20:08:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 180483b8235b6b56e9d7f4d8a6ae85ff SHA-1: 5734caf58479afe6fd5b401fdab7ada27d72141a SHA-256: 28275496d8639708725dae124945cec00d059f5ddc1617402bc1df6e063c4671
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting. This suggests the primary goal is to redirect users to potentially malicious sites, possibly for phishing or SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9704

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://ondrejkocar.cz/img/file/jedorenikinawu.pdf In PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/16077e31914cf8---30011591320.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609247ce9dc7c---20899330959.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/1891a6284cab085f9a05525ff24e92e8/mobitodaxolog.pdfIn PDF document text
    • https://artigianoteca.it/file/4331878841.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b0a1d2bcc02---fitabasuvegu.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/e3940858e2b9c5e7e37d8280461730e6/zudakirojefun.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d1904915d60---zavalinamugawanemojuzis.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b2aeec04cda---voxemovedon.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-4-29/20210429212437703453.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/988nqta4as3831sd8mt3ccu3av/pidigigilifu.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b7e4af5712b---97220959638.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/221e4a0a07bd799f94846cc39d74df13/dazodezajikumaxufax.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/2d519371a9a0557bc929227ed30281d4/kinevuwoxeludufuripadawuz.pdfIn PDF document text
    • https://aradovan.com/userfiles/file/2626428992.pdfIn PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/zigej.pdfIn PDF document text
    • http://geometramaurotozzi.it/userfiles/files/siniku.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/31c11ceaecb4ad07f14bb6aa722bb697/pofowifune.pdfIn PDF document text
    • https://vietucmould.com/img-vietuc/files/79896938215.pdfIn PDF document text
    • https://www.freshstartdigitalmarketing.com/wp-content/plugins/super-forms/uploads/php/files/c79ce8afc0d8d3e3b32edb5bdf63d183/muvuwojovunupinur.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160871c0f8a5ea---29982438297.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c106aa59524---53209461974.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/qlokd1du480682nk13lnbd5hnb/52924267140.pdfIn PDF document text
    • http://angelcabrera.com/FCKfiles/file/60383176774.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b8463ccd4c---3250784024.pdfIn PDF document text
    • http://gchsclassof1970reunion.com/clients/6/6a/6a45fbe13d63dbb0eb8070d7cb9dbc89/File/nilebexamovemewanurunez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=the+oxford+handbook+of+philosophy+of+emotion+pdfPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fd52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD52 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001155f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1155F 7724 bytes
SHA-256: 724dd7b6032b2859f66a160b83852a191667db158ccfe396c1a2f13b832ed098
font_02_sfnt_off00012f3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F3A 18204 bytes
SHA-256: 935133af2781b4e4333cf6150a12ef85db145a4121aa42952120e2b48cde662f
font_03_sfnt_off00015e99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E99 11172 bytes
SHA-256: 7ba27e4484419ba54517c86455731bc3d8e9dfb425741d2a5cdbd929bbcf8e1d