Malicious PDF — malware analysis report

Static analysis result for SHA-256 77cda19f88bc888a…

MALICIOUS

PDF

68.7 KB Created: 2021-02-11 10:55:49 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: 22a03909fd2aef419fdc65a069a397a6 SHA-1: 198c08ffe1e03e4ede3eb274ccd0714235806f4b SHA-256: 77cda19f88bc888a12da694a8c1c0c58e7158750cb10ffb42dfde6cbe416bc73
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF contains a large number of embedded URLs, many of which point to known malicious redirectors or disposable hosting, indicating a link farm designed to lure users to malicious sites. The ClamAV detection and ML classifier further support its malicious nature, likely as a phishing or malware distribution vector. No scripts were extracted, but the PDF structure itself is used to facilitate the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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/123?utm_term=ocean+current+worksheet+answer+key In PDF document text
    • https://cdn.sqhk.co/xororasomig/LidM2hf/mini_games_servers_for_minecraft_pe.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4377115/normal_6001d39235d91.pdfIn PDF document text
    • https://rakuwogu.weebly.com/uploads/1/3/4/8/134858672/kunofona-dareveviv-pebolaz.pdfIn PDF document text
    • https://wazexusevawixi.weebly.com/uploads/1/3/0/7/130776334/8230608.pdfIn PDF document text
    • https://cdn.sqhk.co/supopareso/cigQrBT/can_you_escape_100_room_2_level_12.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408343/normal_601b0d9d6f541.pdfIn PDF document text
    • https://cdn.sqhk.co/dakuwuwuzije/XTijhgu/royal_guard_fish_and_chips_danbury_connecticut.pdfIn PDF document text
    • https://mufosuxid.weebly.com/uploads/1/3/4/0/134040625/podefaxotom-lekegigog.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491412/normal_5fd6b1ac35486.pdfIn PDF document text
    • https://cdn.sqhk.co/lewikokezina/JFiabih/shark_ionflex_duoclean.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459325/normal_6023c743d1d9f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4427783/normal_5fd039cc250a7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448724/normal_60249b0017494.pdfIn PDF document text
    • https://cdn.sqhk.co/zivuzigup/8oldiaz/novo_cinema_dubai_festival_city_now_showing.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497358/normal_60244ade192dd.pdfIn PDF document text
    • https://lalibirubifo.weebly.com/uploads/1/3/0/8/130873838/456d0b21fb17.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/vatosolikijike/dexotopofagavol.pdfIn PDF document text
    • https://s3.amazonaws.com/bejokazemur/adeste_fideles_partitura_coro.pdfIn PDF document text
    • https://s3.amazonaws.com/fasudikek/ccna_online_study_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/migivewuwe/tipokugub.pdfIn PDF document text
    • http://punolubumima.epizy.com/tuvuxudip.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_off0000d19f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD19F 5140 bytes
SHA-256: 27cb8738fac1fe447f537c394eeb66d0687073e35e3a8217d5bcb74cd585479b
font_01_sfnt_off0000e32d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE32D 9900 bytes
SHA-256: 69eafea4a6b82f50e363da14cf62124d520beee88c60035ed8679f7097b2ca0f