Malicious PDF — malware analysis report

Static analysis result for SHA-256 8244fc8499a8f2e3…

MALICIOUS

PDF

81.0 KB Created: 2021-04-06 16:32:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 0ec23b2e181e2e4dbda3985bd14da13e SHA-1: 6260166ae83b15bc5aab55bbe6a9d9d9f7ee112d SHA-256: 8244fc8499a8f2e32cecbe14d2435ce4c263c11be18e5a39dad5abd4d11dd3ad
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, specifically identified as a phishing trojan. While no scripts were directly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to potentially malicious or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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://midufefew.ru/123?utm_term=rcog+green+top+guidelines+ectopic+pregnancy PDF link annotation
    • http://mosasekoz.22web.org/word_order_exercises_with_answers.pdfIn PDF document text
    • http://gusevoxuzuwelap.mywebcommunity.org/20487497912.pdfIn PDF document text
    • http://dorulezebum.sportsontheweb.net/68917258433.pdfIn PDF document text
    • http://forpost-electrica.ru/66188928815y2c0i.pdfIn PDF document text
    • http://gunofixe.medianewsonline.com/6150471889.pdfIn PDF document text
    • http://prizinsta365.online/rufebodotojukagkv0w.pdfIn PDF document text
    • http://neroveruturom.iblogger.org/bsc_nursing_form_2019_haryana.pdfIn PDF document text
    • http://tobafiga.medianewsonline.com/answering_islam_download.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/3204972b-28a7-4426-aa50-ca8c5665d582/how_to_learn_corel_draw_step_by_step_in_hindi.pdfIn PDF document text
    • https://91e55214-10ad-44cf-a10a-60a9392df58b.filesusr.com/ugd/e1c37d_b87c2a472c1441bfab15217eb0ae4771.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/57505b58-f2aa-4411-b0ae-e3848bb4dad1/who_invented_the_first_internet_browser.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c13e6a6-5720-4e31-b0db-4155fcf7df45/xarujenilarimidewi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0e6a3468-3501-499b-abd0-29e18877c567/wubibitemisubawodevon.pdfIn PDF document text
    • https://793776f3-68b4-44d3-947a-596ce2c6f652.filesusr.com/ugd/4e977a_33b5c45e171f4f01afbbd081641aade6.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/ad5b29a8-4cdb-4b53-b171-755e1ddca856/15842960442.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f4a1ff6c-c1ba-426f-a86b-9830cddcd346/t_fal_ez_clean_deep_fryer_how_to_use.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2d2b4435-4773-49ff-9f90-d7042b94eee2/app_para_aprender_ingles_nios_3_aos.pdfIn PDF document text
    • http://polilofu.onlinewebshop.net/third_type_conditional_exercises.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f203.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF203 5232 bytes
SHA-256: 8f2dcd3ad7eb60c76fa27cbf15f5ac8739785fc0b0e529f784669ea1d5a775fb
font_01_sfnt_off000103e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E1 10792 bytes
SHA-256: ce75916a44e4f4d582c0825912fee228a95e381c03551301705db8cfd79fbdae
font_02_sfnt_off00012882.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12882 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f