Malicious PDF — malware analysis report

Static analysis result for SHA-256 921cec16cb96cb99…

MALICIOUS

PDF

85.5 KB Created: 2021-06-03 11:37:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: a18c2a3acc19966da3a390b732533f29 SHA-1: 517b0cefeea068f320355dc9e4c9061f1ec17542 SHA-256: 921cec16cb96cb9965679d00fecb7308b1d17860612834a251ff268f0493ce71
226 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a clipboard-command (paste-and-run) lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 7

  • 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.
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • 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://medvor.ru/pbw?utm_term=how+to+make+a+new+branch+in+git+terminal PDF link annotation
    • https://nenejafaf.weebly.com/uploads/1/3/5/3/135393494/xabijaj.pdfIn PDF document text
    • https://venolebibu.weebly.com/uploads/1/3/5/3/135348563/0feee5f2c5a3c7e.pdfIn PDF document text
    • https://mawakigimewu.weebly.com/uploads/1/3/4/8/134875352/6209916.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/ea4238c8-ad75-407a-a9b2-78c33b5a3c74/stickman_and_gun_3_zombie_shooter_mod_apk_hack.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/317ce38e-8aa0-4774-8864-3a109f7cfd32/91189061876.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/002d7d6d-4325-4e5d-ae8d-665d8b7b4dba/wujafinimiwuvoburijisoxu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/307ad2a7-2e6b-48e5-94e5-e7ba827438ca/what_is_flemings_left-hand_rule_used_for.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/96e3d1c9-5d02-4bd7-b922-a0e14bc8af84/zirow.pdfIn PDF document text
    • http://vawijoj.pbworks.com/f/kevinubi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8505c8df-a022-4c06-b55f-3173d9074800/maxi_cosi_pria_85_forward_facing_recline.pdfIn PDF document text
    • http://liwuvedesisu.pbworks.com/w/file/fetch/144492828/letter_to_santa_template_free.pdfIn PDF document text
    • http://kinuwibe.pbworks.com/w/file/fetch/144443451/38819520824.pdfIn PDF document text
    • http://natizasex.pbworks.com/w/file/fetch/144411435/human_genetics_concepts_and_applications_12th_edition_by_ricki_lewis.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ad535b79-a442-478f-989a-14970a0a7917/80913263926.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6abb623c-cf3e-4c32-94cd-8f1b6806f36a/zumaxujivoxorelumijok.pdfIn PDF document text
    • http://sizolasipape.pbworks.com/f/what_are_the_4_major_marine_biomes.pdfIn PDF document text
    • http://viluxese.pbworks.com/w/file/fetch/144413289/free_printable_grammar_worksheets_for_4th_grade.pdfIn PDF document text
    • http://fuvesiwowegu.pbworks.com/w/file/fetch/144413526/fokolodinurakasitezo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/791b04b8-cd54-47f6-ac9a-993b68fd8b7f/what_is_the_power_of_self_knowledge_essay.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/12c1b07d-bf40-417b-8b3b-c53626b404c4/pilizarulupejufowarej.pdfIn PDF document text
    • http://negaboxa.pbworks.com/w/file/fetch/144479295/kufitodutapiwidiribewe.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
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6B 5292 bytes
SHA-256: 2f1bead89bab1d37261b001e58a4203e9b285b1f48643c15850f6a7c5dc62c88
font_01_sfnt_off00010c4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C4E 11040 bytes
SHA-256: 74e33640caac8c3632e47d6ad7cadbcbe1ee2df1a03e7e7e1b12973ec7ed7ba2
font_02_sfnt_off0001327e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1327E 16388 bytes
SHA-256: 0c82561ead172ac0e51412abe629b5944d5f81f469066018c017fef234fe4ba7