Malicious PDF — malware analysis report

Static analysis result for SHA-256 a156b37cc226420f…

MALICIOUS

PDF

96.6 KB Created: 2021-02-15 20:28:01 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 52e5c18fc7823e288e34c037a82ff321 SHA-1: 3d9d26cb10db633e0e677ccbd825feb0b0c67c9e SHA-256: a156b37cc226420f42379c5409f2092f4ee6c8775583aa9b100bec82a69b2ffb
244 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, many of which point to known malicious redirector infrastructure or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body, though heavily obfuscated, contains text related to downloading themes, suggesting a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://yafferge.ru/wix?keyword=download+go+keyboard+theme+apk In PDF document text
    • https://cdn.sqhk.co/woteruzid/sgdIjhp/11313667125.pdfIn PDF document text
    • https://cdn.sqhk.co/wufevinek/A1Cvigg/20334350119.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489052/normal_601a3b54db055.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415929/normal_5fd711d730324.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457279/normal_5fdbdc1a4d7cb.pdfIn PDF document text
    • https://varudigenaka.weebly.com/uploads/1/3/4/5/134597471/891172632.pdfIn PDF document text
    • http://fokuwezowixo.iblogger.org/simple_disney_piano_sheet_music.pdfIn PDF document text
    • https://xonifosanonozo.weebly.com/uploads/1/3/2/6/132680915/sozixele.pdfIn PDF document text
    • http://xevozunufu.iblogger.org/34147394612.pdfIn PDF document text
    • https://cdn.sqhk.co/fokatekox/XfifFdR/76980908303.pdfIn PDF document text
    • https://cdn.sqhk.co/dedikunakudu/jhhgc75/medesagusire.pdfIn PDF document text
    • https://cdn.sqhk.co/nepusoliweda/jiajdie/96507145031.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • http://vatifijagix.epizy.com/laravel_5_change_date_format.pdfIn PDF document text
    • https://s3.amazonaws.com/fedure/possessive_pronouns_spanish_worksheet.pdfIn PDF document text
    • http://retipike.rf.gd/59513248844.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text
    • http://www.gnu.org/licenses/gpl.htmlIn PDF document text

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_007_off000147e2.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x147E2 19192 bytes
SHA-256: 38a2d115a1e0eed80e891cec115620d9ff3a80b4da3bf25bafaa370a7396bbf0
font_00_sfnt_off0000e324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE324 3776 bytes
SHA-256: 5c8ce053674138b26c742fb08c873334dbf42af59d115025b7f97cdbf689aa8f
font_01_sfnt_off0000f0b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B3 5592 bytes
SHA-256: 677ae53a4f90f9bb72a574f07595ed75ead38ea4ba7d7c247e638267816f74bb
font_02_sfnt_off0001039e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1039E 6148 bytes
SHA-256: 149738eb3e1d0bfb4a5732e89a115965e6f0cf3fc4971c694d3ce3619176544d
font_03_sfnt_off0001137d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1137D 17992 bytes
SHA-256: 7e64475437bdc375ab1144993dd596b25850c6e52bf6389c93c1df2bc74b6144
font_05_sfnt_off00016825.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16825 2832 bytes
SHA-256: ee8afa51e50492bdf4d25b6b01818d2021856a0eb5271b70f188e6d094f25891