Malicious PDF — malware analysis report

Static analysis result for SHA-256 71a3a1db1cdd15be…

MALICIOUS

PDF

70.9 KB Created: 2020-11-10 20:28:56 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9dbfa28bf49763f6087c4b5d35df4718 SHA-1: 97f51fc6dc8db28696f189a0b3afb61ae48b97c3 SHA-256: 71a3a1db1cdd15be875b8c593088773eda29e6a4d13d7155c11ea47f2570d631
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external links, identified by the PDF_SEO_LINK_FARM heuristic, pointing to a large collection of other PDFs. One of these links, 'https://traffnew.ru/123?keyword=accustomed+mean+in+urdu', is directly embedded. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution through this link farm.

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://traffnew.ru/123?keyword=accustomed+mean+in+urdu
    • https://meboguvogo.weebly.com/uploads/1/3/1/4/131437667/a8fa3155.pdf
    • https://cdn-cms.f-static.net/uploads/4387931/normal_5f9a3c6b190d8.pdf
    • https://rikudebuwixe.weebly.com/uploads/1/3/4/5/134589128/3915489.pdf
    • https://cdn-cms.f-static.net/uploads/4379054/normal_5f92aef2863ed.pdf
    • https://gozajajemitala.weebly.com/uploads/1/3/4/3/134325553/lopidumedamotisiseza.pdf
    • https://kiriwalukejogof.weebly.com/uploads/1/3/4/3/134310578/sikelelefuguze.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/8d99a1cd-210e-4973-b0d6-e86daae78ccc/nunefuruxepo.pdf
    • https://uploads.strikinglycdn.com/files/7aad8790-8a41-4954-aabe-47047d7afb11/20163243760.pdf
    • https://uploads.strikinglycdn.com/files/49d62f84-2fdb-48ba-8eae-145657756541/freight_train_tab_songsterr.pdf
    • https://uploads.strikinglycdn.com/files/60f9d91c-26f4-4f58-b2fd-15a423d2dd17/80226970855.pdf
    • https://uploads.strikinglycdn.com/files/6bd3afb9-5704-4cc8-a99d-b0aaf2e4bace/81438823299.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
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c109.bin
41c59678b2eaa813233376a74e42ac858c29878b9f8b031c084535ebcea1c146
pdf-font-stream PDF embedded font (sfnt) at offset 0xC109 5044 bytes
font_01_sfnt_off0000d213.bin
58ef2b7d4f8daef583bd7825869521222bd7097dd1d8c4fd2f1d078422ed72d1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD213 10328 bytes
font_02_sfnt_off0000f5ab.bin
c566dd05a19564c5c566667208aa0b64e17c50a0cd5dab8a536e2fff63f877f7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5AB 17372 bytes