Malicious PDF — malware analysis report

Static analysis result for SHA-256 50df620bda4ec040…

MALICIOUS

PDF

73.9 KB Created: 2021-03-12 12:51:04 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: b8dc3e1807776aa9059c8b5a3e13ae27 SHA-1: 0270c6e8bf8d33b5142dbe04a46d5652c91bceeb SHA-256: 50df620bda4ec0405df4005986f4bcbc511e83dede9cc200bfd753ea15b4c939
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains a large number of external links, identified as a link farm, with many pointing to disposable hosting. This behavior is indicative of a phishing or malware distribution scheme, likely intended to lure users into downloading malicious files or visiting compromised sites. The ML classifier and ClamAV detection strongly support the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://vilenefex.ru/123?utm_term=bodoni+book+italic+font PDF link annotation
    • https://cdn.sqhk.co/rubuxupab/ajbhjDn/snap_and_cash_assistance_mn.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4426410/normal_5fedb8ace0db2.pdfIn PDF document text
    • https://cdn.sqhk.co/mudemodox/hghizje/battle_tank_2_players.pdfIn PDF document text
    • https://cdn.sqhk.co/litigoruf/ihjLPgd/estimator_job_application_cover_letter_best.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4424982/normal_5fed758a4fa77.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380380/normal_6046e9f33efb5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403270/normal_5fee83ef98d1c.pdfIn PDF document text
    • https://cdn.sqhk.co/jawubibegeba/djcHjjh/popijasosax.pdfIn PDF document text
    • https://cdn.sqhk.co/zifixanuk/aXiiPwN/mini_car_racing_download_iso.pdfIn PDF document text
    • https://cdn.sqhk.co/kobewudojuvo/gIibjcZ/ottoman_empire_during_age_of_exploration.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393028/normal_5fdc447dbf46d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476002/normal_6031c3a1297fa.pdfIn PDF document text
    • https://cdn.sqhk.co/giwitosak/fcicLtp/25681470452.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502178/normal_6027e2fd56c19.pdfIn PDF document text
    • https://cdn.sqhk.co/dudugetogi/5XZFQOQ/osm_scout_assistant_ios.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://0dd0cd87-80d3-4eb5-b9c6-73c43c3a6fca.filesusr.com/ugd/f0b6b3_06c0e1ef8eaf4bb9bd7be00bb3d7969d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/pibabopuduj/accident_report_florida.pdfIn PDF document text
    • https://s3.amazonaws.com/dubiditiginowo/jifoximibuxejaz.pdfIn PDF document text
    • https://4a0f17ac-6ce6-4c05-9546-25c48d39d9f7.filesusr.com/ugd/cd79e3_5effcb97ae4541d5bde63bd7d76bf390.pdf?index=trueIn PDF document text
    • https://add83a7c-0e31-48b3-928b-061d82ba9144.filesusr.com/ugd/205ae4_a68484b8083847ce9c5022e1c2559f53.pdf?index=trueIn PDF document text
    • https://4a31e3f8-49e3-4331-b1a9-c0bb7a6b9dbc.filesusr.com/ugd/599f1c_e8265ce83d3943678fd8e60ade6bacb9.pdf?index=trueIn 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e400.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE400 4992 bytes
SHA-256: 3140d72fc24a6e8fed2d5a744b4cb4cb1cff0dc7c15c906cd9826d42136de757
font_01_sfnt_off0000f51d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF51D 10972 bytes
SHA-256: 25831e4ac84df0c08c4dbec57982cfe27e1e95977c7a905ae6e5f7c9bf2eafba