Malicious PDF — malware analysis report

Static analysis result for SHA-256 e72f8f028b66a895…

MALICIOUS

PDF

95.5 KB Created: 2021-02-10 19:46:48 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: b783e21c9c689ef91e451eafbb696d98 SHA-1: 85fd011f387dfefcd4771392aa611b1909bb22d8 SHA-256: e72f8f028b66a89509de100a27a8dc6f73fd743963741055873ab2712de28686
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or phishing lure. ClamAV detected this as 'Pdf.Phishing.Trojan', and ML classification strongly flagged it as malicious. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jacksth.ru/123?utm_term=standard+enthalpy+of+formation+chart PDF link annotation
    • https://cdn.sqhk.co/dapubebireba/hdTM268/fist_of_the_north_star_lost_paradise_yakuza.pdfIn PDF document text
    • http://cyberlife.store/carlcare_uganda_jobsqpl7k.pdfIn PDF document text
    • https://cdn.sqhk.co/lakekomum/bidiejf/57406796148.pdfIn PDF document text
    • http://reawolt.online/denon_home_audio_equipmentaf686.pdfIn PDF document text
    • https://cdn.sqhk.co/gitovera/l2jigjg/saxegavesokate.pdfIn PDF document text
    • http://reduslimitalia-oficial.site/6426760035s0tfd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4409421/normal_5ffd54808bb9d.pdfIn PDF document text
    • https://cdn.sqhk.co/rubupidorinu/ckTUeid/nunodiwavemelapi.pdfIn PDF document text
    • https://posilopawirina.weebly.com/uploads/1/3/4/3/134353572/dinesoxurefizov_furamuf.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366005/normal_5ffa66c1b49be.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413017/normal_60059ebe4cba4.pdfIn PDF document text
    • http://fortuneocredit.com/79580268310nx213.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486521/normal_5fda68d444ddb.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://suzogoga.epizy.com/snowball_viburnum_tree_form.pdfIn PDF document text
    • http://jojisoxig.epizy.com/tukoxu.pdfIn PDF document text
    • http://xarozimazog.rf.gd/add_drop_down_list_in_word_template.pdfIn PDF document text
    • 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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f4b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B1 6600 bytes
SHA-256: 8f97787a98c1393565a74ecc7841718c6ce1318e2efe62e3dff35bae59e0a228
font_01_sfnt_off00010539.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10539 5424 bytes
SHA-256: 68d537a93635337a6299d27750ef979325475d94704a341bf6932b0529184c64
font_02_sfnt_off0001178e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1178E 15692 bytes
SHA-256: 0241b267d0b6c39ddfc50f82d4fed48ff1f456c2450223d5fa34e019745d8011
font_03_sfnt_off00014a5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A5A 16436 bytes
SHA-256: d8778ea69ccca073495d3dbdf2bf6a8a6e4cfecb486fc392a5490e6d3cea04e4
font_04_sfnt_off000160a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x160A6 6112 bytes
SHA-256: 4e1edbc130f48b8abdeb88bb6adb42e9c7c7e2755de39243b48f7aa7af93e403