Malicious PDF — malware analysis report

Static analysis result for SHA-256 35d437987334236a…

MALICIOUS

PDF

71.4 KB Created: 2021-03-09 18:50:34 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 2dc620bc2b529109f5b8f2b523d4b045 SHA-1: 5d5eea69084336040cf0c7f4b77c065093cfbfc4 SHA-256: 35d437987334236ab4158ad3412cfbeda894b42214bf9fa99db1e7be53a6684d
186 Risk Score

Malware Insights

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

The PDF document contains numerous external links, many pointing to disposable domains, indicating a link farm or phishing lure. The document body, though heavily obfuscated, appears to be related to a riddle answer, likely a pretext to drive traffic to these malicious URLs. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for malware distribution or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://bologen.ru/wix?keyword=there+are+10+fish+in+a+tank+riddle+answer PDF link annotation
    • http://3203epworthcres.com/jazomukotulaxujadazu6wwz2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373527/normal_603c60f2284ea.pdfIn PDF document text
    • http://parralax.net/74598834718qurt8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4424330/normal_5ffca40a95aa6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482206/normal_60261835b7f26.pdfIn PDF document text
    • http://xadexawufomovi.sportsontheweb.net/86935204150.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446015/normal_60253a4614e15.pdfIn PDF document text
    • https://tajifajedu.weebly.com/uploads/1/3/1/6/131637014/6941167.pdfIn PDF document text
    • http://trafikcezaodebayisi.com/how_much_does_teeter_hang_ups_cost4ly7w.pdfIn PDF document text
    • https://nosozekime.weebly.com/uploads/1/3/4/6/134634018/newiboxudi.pdfIn PDF document text
    • http://sepoxudozixo.sportsontheweb.net/maytag_quiet_series_100_dimensions.pdfIn PDF document text
    • https://jotavitot.weebly.com/uploads/1/3/0/7/130738821/sidetub_lijas_wodomazaxilode.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488837/normal_6037930a2d759.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4488810/normal_5fc84cd5d10b1.pdfIn PDF document text
    • http://libuwapuvewipev.mywebcommunity.org/bibavanonojeme.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483591/normal_60419ff003f5c.pdfIn PDF document text
    • http://klossheff.xyz/one_l_scott_turowttunc.pdfIn PDF document text
    • https://fusajebotiv.weebly.com/uploads/1/3/4/3/134320253/185e30b4c.pdfIn PDF document text
    • http://fresh-ita.fun/banefudexefagileswhc0q.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402481/normal_5fda3afddb116.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://bajekixizosi.myartsonline.com/nixon_sentry_leather_black__camo_watch.pdfIn PDF document text
    • https://s3.amazonaws.com/mekonulegipero/flute_scales_sheet_music.pdfIn PDF document text
    • https://s3.amazonaws.com/dubiditiginowo/judo_self_defense_techniques.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB62 5292 bytes
SHA-256: 535962ad0bb56ba067c16adf7d2867bac65b0ec97a1ebe3502b68a9da16cf6c5
font_01_sfnt_off0000ed70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED70 10088 bytes
SHA-256: 5317df43876dc54d8f9ef22ad5e9dc7777c599fde73e65573445d6f42000e08f