Malicious PDF — malware analysis report

Static analysis result for SHA-256 da7b8b7788f1d3cf…

MALICIOUS

PDF

79.4 KB Created: 2021-04-09 22:29:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 903488fbf41acad676d625094f5ea68f SHA-1: 27706caac8b90334431ce4d463dc2da704c751fa SHA-256: da7b8b7788f1d3cf915b485bddbc64507d464c136e45e650be0bc2a849aed357
156 Risk Score

Malware Insights

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

This PDF file is identified as malicious by multiple heuristics and a machine learning classifier, indicating a phishing or trojan-like behavior. It contains a large number of external links, suggesting a link farm designed to redirect users to potentially harmful content, disguised as a study guide. No scripts were extracted, but the PDF structure itself facilitates the malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jumiwimov.ru/strik?utm_term=screwtape+letters+study+guide+answers+pdf
    • https://cdn.sqhk.co/xogodapap/bxgcgjc/cartell_report_uk.pdf
    • https://mugakosi.weebly.com/uploads/1/3/1/3/131379948/buwixev_suvokelolerazi_tivuzegom.pdf
    • https://suveruwifofe.weebly.com/uploads/1/3/1/3/131380558/45095a63df933.pdf
    • https://cdn.sqhk.co/zidodovare/ijiYWTJ/preschool_and_kindergarten_curriculum.pdf
    • https://cdn.sqhk.co/nemoludajedu/ZQBmCib/jemofapuvazudigujedenizat.pdf
    • https://cdn-cms.f-static.net/uploads/4387424/normal_5fe620e4d21b6.pdf
    • https://cdn.sqhk.co/vixawutozama/jjjbjbO/box_office_tycoon_mod_apk_happymod.pdf
    • https://cdn.sqhk.co/sadirorig/hhbojff/kobowofuzupunarawebugiw.pdf
    • https://burevojaziji.weebly.com/uploads/1/3/4/7/134729690/fogidu.pdf
    • https://cdn.sqhk.co/bofilewidil/gcSjcUg/disable_lock_screen_windows_10_when_idle.pdf
    • https://static.s123-cdn-static.com/uploads/4498994/normal_5fee43de666b8.pdf
    • https://cdn-cms.f-static.net/uploads/4454558/normal_605385a75f485.pdf
    • https://cdn.sqhk.co/vefemenivu/beggi0E/79438451687.pdf
    • https://tagewojozupuk.weebly.com/uploads/1/3/4/3/134358966/resutaku.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://s3.amazonaws.com/jivuxo/schlage_keyless_touchscreen_deadbolt_be375.pdf
    • https://s3.amazonaws.com/bejexe/what_is_the_chemical_name_for_table_salt.pdf
    • https://uploads.strikinglycdn.com/files/679e15f2-55d3-4594-84ec-cb5ba344e69b/how_do_you_get_hilton_rewards.pdf
    • https://s3.amazonaws.com/zazelujeju/what_is_extradition_in_public_international_law.pdf
    • https://s3.amazonaws.com/nazekisigiduz/brand_guideline_l_g.pdf
    • https://uploads.strikinglycdn.com/files/f7a34a05-b9a7-475f-a057-eceea33b3de2/thinking_fast_and_slow_chapter_14_summary.pdf
    • https://s3.amazonaws.com/jejulurowev/the_law_of_attraction_2011_full_movie_english_subtitles.pdf
    • https://uploads.strikinglycdn.com/files/4a1837da-934e-4628-821d-b36425b2f7dc/98034828379.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e97c.bin
9b1bac739de56e4ebd794bfe4a9cfb6ff97f20345074bf0fe7ebbbab3b095433
pdf-font-stream PDF embedded font (sfnt) at offset 0xE97C 5392 bytes
font_01_sfnt_off0000fbef.bin
d8f4b293cfa63559342947484f981a67c5071301ffa1c11e21c6d45860977799
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBEF 11312 bytes
font_02_sfnt_off000121e9.bin
1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361
pdf-font-stream PDF embedded font (sfnt) at offset 0x121E9 4324 bytes