Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4bb21e7abe572b8…

MALICIOUS

PDF

93.5 KB Created: 2021-04-03 13:11:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: d2abe1862c751758d84916640eb3ddad SHA-1: 936da923b8e7301a6f168d6333776ce47036c2c1 SHA-256: a4bb21e7abe572b8e7e94523d3c5bde27cca22136cb491dbe40c8869894ad893
186 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, many hosted on disposable domains, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://bologen.ru/strik?utm_term=what+is+the+ability+to+apply+knowledge PDF link annotation
    • https://ludamezowi.weebly.com/uploads/1/3/4/1/134131800/tagaponevodivuxosum.pdfIn PDF document text
    • https://cdn.sqhk.co/worijekegir/hp3dhem/50513352.pdfIn PDF document text
    • https://xijutenidipes.weebly.com/uploads/1/3/0/7/130775364/tepubobudanapo.pdfIn PDF document text
    • https://widowajezow.weebly.com/uploads/1/3/4/5/134584852/papababeribu.pdfIn PDF document text
    • http://vazawujuzu.sportsontheweb.net/the_innovators_dilemma_1997.pdfIn PDF document text
    • http://tujukesabegakom.mygamesonline.org/29619177719.pdfIn PDF document text
    • https://cdn.sqhk.co/dowusutitozi/dOSgcgf/70832668866.pdfIn PDF document text
    • http://zokidinodajives.getenjoyment.net/99124783293.pdfIn PDF document text
    • http://vigikigopaloze.medianewsonline.com/list_of_words_with_multiple_meanings.pdfIn PDF document text
    • http://jopagozopive.medianewsonline.com/nutritional_value_of_coconut_water.pdfIn PDF document text
    • https://wemowojek.weebly.com/uploads/1/3/5/9/135993501/5125882.pdfIn PDF document text
    • https://cdn.sqhk.co/befozaxulot/tqgdnig/53687908848.pdfIn PDF document text
    • http://tagoturuluro.medianewsonline.com/betrayal_harold_pinter_play_script.pdfIn PDF document text
    • https://cdn.sqhk.co/jimavidozeze/edgiyKk/kakekejage.pdfIn PDF document text
    • http://wodedutipif.medianewsonline.com/how_to_program_samsung_blu_ray_remote_to_element_tv.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ba3a7bb5-edd2-4228-b29c-cf272df6a868.filesusr.com/ugd/bd1c09_3ff35a69a28843d7836ce53c5516a376.pdf?index=trueIn PDF document text
    • http://nomamazuzut.atwebpages.com/fofit.pdfIn PDF document text
    • http://widepidaba.atwebpages.com/3d_inventor.pdfIn PDF document text
    • https://f3c4034a-4a94-4c47-b6c5-0445626d7bf8.filesusr.com/ugd/655f09_d739e76edbf04d3a8555b75fb4da5cce.pdf?index=trueIn PDF document text
    • http://xutenasejubibe.atwebpages.com/96203950054.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011a20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A20 5536 bytes
SHA-256: 4e3294186b0d18a96c819197bb175c5bc7a853e810efc6bf3088c51a401c9c61
font_01_sfnt_off00012d0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D0D 11272 bytes
SHA-256: 44631ebc51e1b39fb8f110c4154a5a04b6e7bbe1cb47485f4bab75262d2c6df1
font_02_sfnt_off00015388.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15388 16060 bytes
SHA-256: 5b0d2701ab39d2f69c66d7d16c60d8db0b323aa0832947137e757b5401d27330