Malicious PDF — malware analysis report

Static analysis result for SHA-256 b888440a3d70c58d…

MALICIOUS

PDF

82.1 KB Created: 2021-04-25 16:40:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: a1e6ccd29ac97eaf2f864789b709abd0 SHA-1: dbfe51d1de5fd7e04de7367bca30faad24eea7d9 SHA-256: b888440a3d70c58dc04fbd69445adc42218a5339ef3c6e3f8d4229a3f398117b
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 pointing to other PDF documents, indicative of a link farm. The presence of a critical ClamAV detection and a high ML score strongly suggests malicious intent. While no scripts were extracted, the structure and URL patterns are consistent with SEO poisoning or phishing campaigns that leverage numerous redirects.

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://pelibifir.ru/strik?utm_term=matlab+simulink+book+pdf PDF link annotation
    • http://ravigimojamel.mypressonline.com/94876621871.pdfIn PDF document text
    • https://cdn.sqhk.co/ruwibinewife/FjeaKjb/cisco_networking_academy_curriculum_5._0.pdfIn PDF document text
    • https://cdn.sqhk.co/zarepowake/Phghjjg/90607312853.pdfIn PDF document text
    • https://cdn.sqhk.co/mogowepuw/dogiidx/73662215717.pdfIn PDF document text
    • https://cdn.sqhk.co/mopomotop/ThfZ7Qe/find_my_phone_android_by_mobile_number.pdfIn PDF document text
    • https://vidapuromojesa.weebly.com/uploads/1/3/4/8/134890941/zebulewa_tunagoveku_buxozozex.pdfIn PDF document text
    • http://kopogaxepaku.sportsontheweb.net/inferior_alveolar_nerve_block_technique.pdfIn PDF document text
    • https://cdn.sqhk.co/wusosekame/jdrticu/ksbw_traffic_reporter.pdfIn PDF document text
    • https://toledopo.weebly.com/uploads/1/3/4/5/134596352/231014.pdfIn PDF document text
    • http://jidapuxedepu.medianewsonline.com/54795141632.pdfIn PDF document text
    • http://zakewabo.scienceontheweb.net/kipakusinano.pdfIn PDF document text
    • https://wugeneziwepuzi.weebly.com/uploads/1/3/4/4/134494794/4000245.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://s3.amazonaws.com/bipepezuwed/how_to_pair_rock_band_guitar_xbox_one.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ddef0680-f25e-4f6e-aa8d-1cddd59da488/wasifovakaluma.pdfIn PDF document text
    • https://s3.amazonaws.com/satuja/63451494051.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6ec0ec16-94e9-4994-9c9a-9d3133c35459/where_can_i_get_a_microwave_near_me.pdfIn PDF document text
    • http://temodorofeg.atwebpages.com/describing_people_s_appearance_english_exercises.pdfIn PDF document text
    • https://s3.amazonaws.com/budovewesekaz/skype_7._56_for_mac.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/74537b85-973c-4fb1-a939-514c913d0f85/how_do_you_cook_cinnamon_rolls_in_a_waffle_maker.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e38cfe27-b825-45f1-89fa-c68787ea35d4/6-1_practice_properties_of_exponents_answers.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_off0000f60b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60B 5064 bytes
SHA-256: 86941fcbb41eb2a1482acf4e62a7d36c6e4af35e955eed98ab95cab793971ee3
font_01_sfnt_off00010726.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10726 11572 bytes
SHA-256: 01893051aa5a1564ce77277d085627eb1b49320da91572c9d0519f69d1033d12
font_02_sfnt_off00012d52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D52 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f