Malicious PDF — malware analysis report

Static analysis result for SHA-256 5af841568c34e417…

MALICIOUS

PDF

83.0 KB Created: 2021-01-30 16:20:48 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 7c129b70aa0352e10ed259b196316064 SHA-1: eb4f0b1f7a5fe3800577c552583a1bb34dc9ddd2 SHA-256: 5af841568c34e4170528fa57b2ed4ecd2c6a29b0c54b4af42a746f9e734ba261
244 Risk Score

Malware Insights

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

This PDF file exhibits characteristics of a link farm, containing numerous embedded URLs pointing to external PDF documents. One URL, 'https://yafferge.ru/aws?utm_term=chordate+embryology+book+pdf', is flagged as a malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO manipulation or phishing. No scripts were extracted, but the presence of many external links suggests a multi-stage attack or a content-delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://yafferge.ru/aws?utm_term=chordate+embryology+book+pdf In PDF document text
    • https://xexidizufom.weebly.com/uploads/1/3/4/5/134508107/d566a8a242f07.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393348/normal_5fefea2c94522.pdfIn PDF document text
    • https://cdn.sqhk.co/nuvexajamu/hjehdig/top_rechargeable_battery_for_sale.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4529281/normal_5fdad2e5e99da.pdfIn PDF document text
    • https://cdn.sqhk.co/xevowuto/lic5hby/xitobem.pdfIn PDF document text
    • https://cdn.sqhk.co/tiviluluje/PiiZigH/jekasofe.pdfIn PDF document text
    • https://cdn.sqhk.co/sibamoxa/jjFxhfR/lily_s_garden_storyline_day_21.pdfIn PDF document text
    • https://cdn.sqhk.co/lozukoxokir/iggcVSk/91326631978.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446917/normal_60027d2fd72bd.pdfIn PDF document text
    • https://verumoxozuvije.weebly.com/uploads/1/3/1/4/131407377/tewofuv_lodurexelelo.pdfIn PDF document text
    • https://cdn.sqhk.co/vapezuwe/cgc6hia/local_music_player_no_ads_apkpure.pdfIn PDF document text
    • https://cdn.sqhk.co/mugejufunij/apcgdjj/ramurolonadiponumap.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4469353/normal_5fe92b6053896.pdfIn PDF document text
    • https://cdn.sqhk.co/tavolimogid/gLhhcip/halloween_party_invitation_ideas_homemade.pdfIn PDF document text
    • https://cdn.sqhk.co/jotoselu/jeQjjig/folefejabujibikoxuxa.pdfIn PDF document text
    • https://xulomonixibeneg.weebly.com/uploads/1/3/1/4/131455416/wupefobuzenado.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4455380/normal_5fce2c86b57f8.pdfIn PDF document text
    • https://sunivisoxeban.weebly.com/uploads/1/3/4/4/134493344/e6943.pdfIn PDF document text
    • https://cdn.sqhk.co/jifigetuxu/hgieq1y/the_sims_free_play_pc_online.pdfIn PDF document text
    • https://cdn.sqhk.co/zanotunuzi/hhmZhg6/bosu_ball_balance_trainer_pro.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/gezetega/uterine_av_malformation_icd_10.pdfIn PDF document text
    • https://s3.amazonaws.com/lofese/wifi_direct_file_transfer_android_to_pc.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_off0001054d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1054D 5488 bytes
SHA-256: 7a9c5a55859869c8b1d66aa50f1eddf9323ecbec7db47c3e0876b22f46080fb9
font_01_sfnt_off000117d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117D1 11504 bytes
SHA-256: 4905126bf480d4e3240222026ca9fa3824615a8d0cf958c3bc0031c823222602