Malicious PDF — malware analysis report

Static analysis result for SHA-256 5e633f96d6f3709a…

MALICIOUS

PDF

79.1 KB Created: 2021-04-01 12:08:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: 422332bdfa963243a874430551b19394 SHA-1: 5e1b86f99c36a333d16941d3b7a9ea6c24f29f50 SHA-256: 5e633f96d6f3709af8c5ff7e0035b454945a007b8e18349bdbff1680cbb7e5c0
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file contains a large number of embedded links, many of which point to known malicious redirectors or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. The document body is heavily obfuscated and appears to be junk data, but the presence of numerous external links is the primary indicator of malicious activity.

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
  • 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://dafemum.ru/strik?utm_term=literary+terms+examples In PDF document text
    • https://cdn.sqhk.co/pufowuvikij/ck5ljjS/26485727521.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4405409/normal_600939fadfced.pdfIn PDF document text
    • http://gbo.guru/retutuburenitadebe2trk.pdfIn PDF document text
    • http://affilateapp.online/bissell_proheat_2x_pet_pro_instructionstej77.pdfIn PDF document text
    • http://reestr.site/65571133487bhr9s.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402267/normal_602ad5fc76543.pdfIn PDF document text
    • https://cdn.sqhk.co/jawutuwek/idijjhz/viridiana_alatriste_funeral.pdfIn PDF document text
    • https://cdn.sqhk.co/miwavilusaji/hhohbtq/piggy_roblox_skin_doggy.pdfIn PDF document text
    • http://alternativeinfluencenetwork.net/98154682242t4sm8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459628/normal_60216cb8a3440.pdfIn PDF document text
    • http://findssldz.xyz/fingerstyle_guitar_songsd02sc.pdfIn PDF document text
    • http://akillidestekbasvuruformu.online/tissot_1853_womens_watch_price_in_india7rkpl.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384030/normal_605aab7b06d53.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://e40da922-b0e4-44be-9878-2d4898ccab21.filesusr.com/ugd/3a38e0_cadc19fdcf2a415fb2b8ba2d0f4224ed.pdf?index=trueIn PDF document text
    • https://121f8fc1-d270-4171-a721-8ccd656fc20f.filesusr.com/ugd/2ca22b_c2bb068a05e04d899b2c1ad40d41b4a7.pdf?index=trueIn PDF document text
    • https://f856bbc4-01c8-45e4-8891-a53c5ee59fd0.filesusr.com/ugd/8e827e_2a35e8947bbe4492af2d51fdf0807632.pdf?index=trueIn PDF document text
    • https://b54663a3-ff9d-4122-b75c-69b71428c9b0.filesusr.com/ugd/cfa91a_0febccb1f206415383675e55d123bad3.pdf?index=trueIn PDF document text
    • https://77bc4ea4-de20-41c0-a463-a5315db628d9.filesusr.com/ugd/2c69e3_9f00d85e9b104d91b8f4e2c1bafc45bb.pdf?index=trueIn PDF document text
    • https://a52dd608-e7dd-4d50-8005-e0fd7a3896b4.filesusr.com/ugd/43d2fc_90b4befc38c7421994059ee459aefa9a.pdf?index=trueIn PDF document text
    • https://9df6e0af-a028-4e88-91ba-61a1b37318d5.filesusr.com/ugd/7c1f05_f43b318d29cd499eb95daedbe2b0429e.pdf?index=trueIn PDF document text
    • https://3ae4d138-4ba3-4962-98fb-1b98b40a6a82.filesusr.com/ugd/38062a_2f3aad9a9e9446028fcce3a8d795b925.pdf?index=trueIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fb18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB18 5076 bytes
SHA-256: a285876bb5787552396696a51c77928a65677609edd6ee695a51d39963c42bfc
font_01_sfnt_off00010c54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C54 10204 bytes
SHA-256: d86bd0e6922a05aaa22c83e967945180a6bfb7e0f144356874e4ea564044842c