Malicious PDF — malware analysis report

Static analysis result for SHA-256 66b34bd446878493…

MALICIOUS

PDF

77.6 KB Created: 2021-05-22 10:50:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 86b877d158fa3540848d61a928f0b1e8 SHA-1: ea3f07f3c9a417c374149facaf6b23740f8a2929 SHA-256: 66b34bd446878493edbd0118fe7eb866a042b47b5b144d2d448a9a29014f68a0
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to SEO-optimized PDF files, indicating a link farm or phishing attempt. The primary malicious URL identified is https://baarspo.ru/strik. While no scripts were extracted, the PDF structure and numerous external links strongly suggest malicious intent, likely to redirect users to malicious websites or to manipulate search engine rankings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://baarspo.ru/strik?utm_term=coefficient+of+subgrade+reaction+piles
    • https://cdn-cms.f-static.net/uploads/4494889/normal_605c461ae37a7.pdf
    • https://cdn-cms.f-static.net/uploads/4447447/normal_5fd1e71367087.pdf
    • https://static.s123-cdn-static.com/uploads/4413987/normal_5fdfb1581ccc6.pdf
    • https://dunawotota.weebly.com/uploads/1/3/1/4/131438316/zimolozigu_sadadexi_wedex_pesisopox.pdf
    • https://tenogamux.weebly.com/uploads/1/3/2/6/132681545/memaliwotapitil_tepago_rosit.pdf
    • https://sozobuxetezubu.weebly.com/uploads/1/3/4/5/134527793/8062239.pdf
    • https://static.s123-cdn-static.com/uploads/4403421/normal_60075d68196f8.pdf
    • https://cdn-cms.f-static.net/uploads/4408177/normal_6023650845356.pdf
    • https://static.s123-cdn-static.com/uploads/4446643/normal_6000300c59096.pdf
    • https://static.s123-cdn-static.com/uploads/4379486/normal_5ffa27acabb95.pdf
    • https://cdn-cms.f-static.net/uploads/4387920/normal_60228a71b0da3.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://s3.amazonaws.com/dobesogum/samsung_clp_325w_toner_waste_tank.pdf
    • https://uploads.strikinglycdn.com/files/49d8457f-6dc0-4cf8-a5c3-2da06256b765/bonorenimozizut.pdf
    • https://uploads.strikinglycdn.com/files/7e90991f-5461-4459-a8ca-adfd3e6b15be/bagusi.pdf
    • https://s3.amazonaws.com/jajoxulabojaso/42836929514.pdf
    • https://s3.amazonaws.com/bomupi/case_study_resistance_to_ddt_answers.pdf
    • https://s3.amazonaws.com/xuzakob/guitar_chord_sheet_music_for_beginners.pdf
    • https://uploads.strikinglycdn.com/files/d3dae60a-3f6f-406d-ab84-dce5ee877c8e/41034015829.pdf
    • https://s3.amazonaws.com/fobupojowojon/gojixomabekamofa.pdf
    • https://uploads.strikinglycdn.com/files/a70435e4-6882-468f-8194-4125bf5b8238/girl_scout_song_lyrics_philippines.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_off0000e362.bin
208687070176f171d32171cd94e3446a8a5598ac229ab13dad2794d4252fb1f4
pdf-font-stream PDF embedded font (sfnt) at offset 0xE362 5368 bytes
font_01_sfnt_off0000f5a8.bin
b45610552cb67a1ac7cf4f40a2ce2feeeaf62c7a39f2c521d85a136908a0b268
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A8 10508 bytes
font_02_sfnt_off00011960.bin
1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361
pdf-font-stream PDF embedded font (sfnt) at offset 0x11960 4324 bytes