Malicious PDF — malware analysis report

Static analysis result for SHA-256 99f9628c3cd8e9cc…

MALICIOUS

PDF

79.0 KB Created: 2021-04-08 05:49:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 3d69ab49174c4f614cc2de6434a6067a SHA-1: e79fbc3e777e77842ae50722c7ba11530f266d9c SHA-256: 99f9628c3cd8e9ccd419fcf88472cae989ed621de1bd4e7c46dcfe19a51c11fa
244 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, many pointing to known malicious redirectors or disposable hosting, suggesting a phishing or malware distribution campaign. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the nature of the links and the heuristic firings point towards a malicious document designed to lure users to harmful sites.

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://dafemum.ru/wix?keyword=the+crucible+final+exam+answers In PDF document text
    • https://cdn.sqhk.co/zugivakizo/iPBtxgj/70964780218.pdfIn PDF document text
    • http://masirudukumope.iblogger.org/english_brushup_5th_edition_free.pdfIn PDF document text
    • https://rusakubasarozu.weebly.com/uploads/1/3/4/2/134266120/pobatuv-nopegitubalobig.pdfIn PDF document text
    • https://cdn.sqhk.co/moxelutedoje/nhhjium/58243538685.pdfIn PDF document text
    • https://jupolojujilozas.weebly.com/uploads/1/3/4/5/134598947/6026200.pdfIn PDF document text
    • https://dunufofobepo.weebly.com/uploads/1/3/4/3/134380723/rabelorawiv-savepujefi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369766/normal_604647b57a157.pdfIn PDF document text
    • https://fejilezujew.weebly.com/uploads/1/3/4/3/134340931/3796101.pdfIn PDF document text
    • https://cdn.sqhk.co/posojuvapono/aIibF5F/assistir_videos_youtube_offline_ipad.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420939/normal_60489088420ae.pdfIn PDF document text
    • https://cdn.sqhk.co/tadawatimi/b2diigj/scientist_names_and_their_inventions_list.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370286/normal_605d9f977f2f9.pdfIn PDF document text
    • https://motanaweda.weebly.com/uploads/1/3/4/3/134316912/bojikelenupojisepuk.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470839/normal_602db04af00fa.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://f3c4034a-4a94-4c47-b6c5-0445626d7bf8.filesusr.com/ugd/655f09_d23d9b8b669c497c9504e94fd013f6d4.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/8ab22062-9116-4432-9693-64156f4a0292/how_to_fix_mtd_snowblower.pdfIn PDF document text
    • https://4e4301d6-cc9a-4939-960a-6b497c1efea6.filesusr.com/ugd/d78803_6d80cf86993b439798c36a54112f39b2.pdf?index=trueIn PDF document text
    • https://98e80eac-0673-4bf9-a3de-4132461903b3.filesusr.com/ugd/1acd69_60e8fc8d063e4483b94ed191af62aacf.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/d0581862-b9e2-46f6-953f-d088636743ac/10000_reasons_mat_redman_chords.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0596d5a9-9141-442c-a389-860fb327e640/wudodimowawapaj.pdfIn PDF document text
    • http://migukim.rf.gd/murobovub.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_off0000f648.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF648 5368 bytes
SHA-256: ef0c626416824ab490655072b13d318b5df29be8946c355945dd518fe30314f1
font_01_sfnt_off00010877.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10877 10580 bytes
SHA-256: 665e50f9d455a440c0a0c392983aeedc4ee305623f1a524379394f15aac1bcb0