Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0c470f3a7735f3f…

MALICIOUS

PDF

70.7 KB Created: 2021-01-13 08:24:28 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dc860e9b8c6a880f81be4d7fe50ec8a7 SHA-1: eee850f9050353f0ca1c95459e5aee1ea512eb9a SHA-256: a0c470f3a7735f3f6790639373a70edfb8d1cbb0fd0884c063d60da852448c9f
156 Risk Score

Malware Insights

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

The sample is a PDF document identified as malicious by ClamAV and an ML classifier. It contains a large number of external links, indicating a link farm or redirection strategy. One of the extracted URLs, 'https://trafficel.ru/123?utm_term=small+bear+electronics+review', is directly referenced by a PDF_URI heuristic. While no scripts were explicitly extracted, the PDF structure and extensive linking suggest an attempt to direct users to potentially harmful external sites, possibly for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://trafficel.ru/123?utm_term=small+bear+electronics+review
    • https://site-1191329.mozfiles.com/files/1191329/93236841488.pdf
    • https://cdn-cms.f-static.net/uploads/4503987/normal_5fd5f8430eebd.pdf
    • https://cdn.sqhk.co/gekobegij/2ihgfuL/ant_war_full_game_unblocked.pdf
    • https://site-1178784.mozfiles.com/files/1178784/85379370732.pdf
    • https://kedaweva.weebly.com/uploads/1/3/4/8/134895813/4e25d.pdf
    • https://site-1175951.mozfiles.com/files/1175951/lullaby_music_for_babies_in_the_womb.pdf
    • https://guromofir.weebly.com/uploads/1/3/4/4/134489627/bifefosum.pdf
    • https://cdn-cms.f-static.net/uploads/4453888/normal_5fd338fb76799.pdf
    • https://static.s123-cdn-static.com/uploads/4451549/normal_5fe19fde581c6.pdf
    • https://static.s123-cdn-static.com/uploads/4407327/normal_5fe406620f94e.pdf
    • https://cdn.sqhk.co/munuluxel/vihsqEa/najibabepibesogo.pdf
    • https://cdn-cms.f-static.net/uploads/4469827/normal_5fa6f4efae98a.pdf
    • https://cdn.sqhk.co/bexoninodag/mjbggsu/59403900730.pdf
    • https://cdn.sqhk.co/wazafanez/ieihidc/renaxesapogulobofibow.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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_off0000d60b.bin
e34e821ce615ba8cdd090676803b80c87ab9ee0468929088fae8f25701582ec6
pdf-font-stream PDF embedded font (sfnt) at offset 0xD60B 5340 bytes
font_01_sfnt_off0000e82d.bin
656a75f269159a730312ec969725d44b27ac676cce1c36ddbf2e0525612da7ac
pdf-font-stream PDF embedded font (sfnt) at offset 0xE82D 11216 bytes