Malicious PDF — malware analysis report

Static analysis result for SHA-256 498353cb50ec1a94…

MALICIOUS

PDF

78.6 KB Created: 2021-04-15 11:46:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 24c04bc8fe52b23ee3ec637e9cdea89a SHA-1: e6bbf3f9a9e49fa76ebffd05d67fbda96e1bdd33 SHA-256: 498353cb50ec1a94ba29ca114492071b391f5a20fdb123d31809c8447706fd42
186 Risk Score

Malware Insights

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

This PDF document was flagged by multiple heuristics as a link farm, containing a large number of external links pointing to potentially malicious or disposable hosting sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were extracted, the sheer volume of suspicious URLs suggests a coordinated effort to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • 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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jumiwimov.ru/strik?utm_term=visual+c%2523+2012+how+to+program+pdf
    • http://jesubenodewopob.22web.org/ruvag.pdf
    • https://cdn-cms.f-static.net/uploads/4446152/normal_603837cac625c.pdf
    • https://cdn.sqhk.co/mogudekusab/Dhc3Ygc/fovenugovajinumuno.pdf
    • https://nateguwab.weebly.com/uploads/1/3/1/4/131453796/wipixiwujesam.pdf
    • https://cdn.sqhk.co/navimoxa/ji3vkij/sudoku_online_free_hard.pdf
    • https://static.s123-cdn-static.com/uploads/4450516/normal_5fca613e09d77.pdf
    • http://wurozorunabukub.iblogger.org/fafobularanotubedan.pdf
    • https://cdn-cms.f-static.net/uploads/4417426/normal_605c619ba8475.pdf
    • http://jotijop.iblogger.org/queen_s_gambit_chess.pdf
    • https://cdn.sqhk.co/gunumiku/7ijhfgP/57519815098.pdf
    • https://xetutimi.weebly.com/uploads/1/3/0/9/130968997/28b64cad.pdf
    • https://cdn-cms.f-static.net/uploads/4385202/normal_6056ce20a30ac.pdf
    • https://static.s123-cdn-static.com/uploads/4385612/normal_5fed51ad8ec52.pdf
    • https://cdn.sqhk.co/bomoxale/hgpgh7y/spelling_test_worksheet.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • http://gobavaduxa.epizy.com/14664984828.pdf
    • https://18b62485-dce0-4e35-9712-b1d1f13fcb23.filesusr.com/ugd/296484_2b33002b54934089b0a08e4dc7713d88.pdf?index=true
    • https://76a725e8-946c-4ae9-9249-cda469d35108.filesusr.com/ugd/83c8cc_38bbdc092d514ba3a8db56e40c45c029.pdf?index=true
    • https://877305ac-a74e-4e93-918f-f866ec7622df.filesusr.com/ugd/0dac30_cd49609cdb354d1d9185117dac17632a.pdf?index=true
    • https://48e6b720-b653-4920-beb0-7ef171ab6ab9.filesusr.com/ugd/d9d1f5_9bd2fd52740d464abc000d59d3e6f5cc.pdf?index=true
    • https://4900ecec-7ac1-411c-be2c-b077674085c8.filesusr.com/ugd/493135_5281371416e44c1a89940bde2bdbce97.pdf?index=true
    • http://gefegasoro.epizy.com/aia_engineering_ltd_full_form.pdf
    • https://3c8197b3-f999-4f29-b3da-fbdfea3dbf34.filesusr.com/ugd/0047a4_228f30d5633b44adb73c613ef050afc6.pdf?index=true
    • https://6f81cef9-66a2-447d-9e1d-4c0427ef15c5.filesusr.com/ugd/4d935e_afaef97fe2004b19b496cba43b010da9.pdf?index=true
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb42.bin
f7f51e2cb2bc0220ea854950678edd42c797ef7a9060b439af3ca454fd6227dc
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB42 4128 bytes
font_01_sfnt_off0000f930.bin
1255282989ba39bb2d1ca073a7d83b5f2a04128d9040d5299b2033439c2e5eae
pdf-font-stream PDF embedded font (sfnt) at offset 0xF930 11004 bytes
font_02_sfnt_off00011ef2.bin
9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EF2 4324 bytes