Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a6ea20bc0bec0dd…

MALICIOUS

PDF

77.9 KB Created: 2021-05-25 01:27:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 911776e6a868f327221fc98522d8aad4 SHA-1: 8ed474f864856916778f17bfd24d1f2e5958ccfd SHA-256: 9a6ea20bc0bec0dd95799647b6b3ad6bc2a834dc2e9698fd98042930cb035c4d
156 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 benign-looking PDFs, but one critical link to 'xajibur.ru' suggests a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and numerous external links are indicative of a link farm used to obscure malicious destinations or distribute further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xajibur.ru/strik?utm_term=human+anatomy+and+physiology+marieb+13th+edition
    • https://pasadotofeb.weebly.com/uploads/1/3/1/4/131482919/jajew.pdf
    • https://tetagusupawuwag.weebly.com/uploads/1/3/4/5/134586179/sopun-natoxiti.pdf
    • https://zivodigogugev.weebly.com/uploads/1/3/4/6/134664532/zadegaxodijegik_nabuz.pdf
    • https://tetoxoji.weebly.com/uploads/1/3/0/9/130969306/kofotimobizun-zovisasizomi.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/xuxifuzituwu/orasatha_album_video_song_in_isaimini.pdf
    • https://uploads.strikinglycdn.com/files/b17ae8af-d219-49d8-a923-5f1fe8c33c95/71251227679.pdf
    • https://uploads.strikinglycdn.com/files/0ad72ff8-09f0-4d71-8f23-49c6ecda7f7c/free_fillable_printable_family_tree_template.pdf
    • https://s3.amazonaws.com/zumomasugipeno/41182154623.pdf
    • https://s3.amazonaws.com/kosipefojaw/internship_acceptance_letter_template.pdf
    • https://s3.amazonaws.com/tiduro/bamufulepopobi.pdf
    • https://uploads.strikinglycdn.com/files/8c77d002-e57f-43d2-a8eb-03111f2ab69f/galarobikov.pdf
    • https://s3.amazonaws.com/jeponowon/fifulirusodadimapanavej.pdf
    • https://uploads.strikinglycdn.com/files/f352050d-bb94-43e4-af79-94b566f524d3/alesis_dm10_owners_manual.pdf
    • https://s3.amazonaws.com/wajibile/ziriligabatilor.pdf
    • https://uploads.strikinglycdn.com/files/1f8529b4-1811-46da-9f28-84b7b3918b77/how_do_i_get_a_religious_exemption_for_vaccines_in_georgia.pdf
    • https://uploads.strikinglycdn.com/files/0d94a606-3e34-4c63-a15f-0ed5a6079269/52811932706.pdf
    • https://s3.amazonaws.com/mixanaz/51900300344.pdf
    • https://s3.amazonaws.com/mupukesunobaga/asphalt_8_airborne_for_mac_free.pdf
    • https://s3.amazonaws.com/debiwelof/afro_house_samples_free.pdf
    • https://s3.amazonaws.com/pulavokaxe/la_times_crossword_answers_11_17_19.pdf
    • https://s3.amazonaws.com/figugipopar/what_are_density_dependent_and_independent_limiting_factors.pdf
    • https://uploads.strikinglycdn.com/files/87f7eb40-6470-46d7-8b5a-6fc93d081503/75545739751.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f3dd.bin
a5ef7c178d4b1bdb0427423a797616066bc974eb4541b12c2b37b1ba0f3190c4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3DD 5792 bytes
font_01_sfnt_off00010774.bin
2df6611ce1b1eeb0250796ae92a8bc51417161bd0185bff5e26111211d9fd393
pdf-font-stream PDF embedded font (sfnt) at offset 0x10774 10116 bytes