Malicious PDF — malware analysis report

Static analysis result for SHA-256 91847b085298acb3…

MALICIOUS

PDF

36.8 KB Created: 2020-09-04 18:38:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ebfcfea35d9a2f1f9bd29fd52d508947 SHA-1: ae3261a7109041ba6713a786c0c066af62131ef7 SHA-256: 91847b085298acb38e06d25b5a4d7c0b943c3f42a0d359878e8cf0eee13ced15
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF file contains a critical heuristic firing indicating it links to a known malicious redirector. The document body, though heavily obfuscated, also contains the same URL. The presence of numerous other PDF links, many pointing to Shopify, suggests a link farm or SEO poisoning tactic to distribute malicious content. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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://ttraff.club/wix?keyword=kaalai+vanakkam+padal
    • https://cdn.shopify.com/s/files/1/0432/0120/0288/files/wisdom_books_of_the_bible.pdf
    • https://cdn.shopify.com/s/files/1/0431/1734/6965/files/qasida_burda_sharif_ringtone.pdf
    • https://cdn.shopify.com/s/files/1/0452/2721/2957/files/free_beginner_classical_piano_sheet_music.pdf
    • https://cdn.shopify.com/s/files/1/0429/6173/1743/files/bukijisaj.pdf
    • https://cdn.shopify.com/s/files/1/0435/2717/6344/files/58349359948.pdf
    • https://cdn.shopify.com/s/files/1/0434/7595/9973/files/jasifelupipodatomamexo.pdf
    • https://cdn.shopify.com/s/files/1/0433/0219/1269/files/navpers_1336_3.pdf
    • https://cdn.shopify.com/s/files/1/0430/4217/7181/files/beginner_guitar_chord_progressions.pdf
    • https://cdn.shopify.com/s/files/1/0431/2458/8701/files/zogebepolujud.pdf
    • https://cdn.shopify.com/s/files/1/0428/8957/6607/files/winrar_for_pc_full_version.pdf
    • https://cdn.shopify.com/s/files/1/0430/9807/9399/files/78123949161.pdf
    • https://static.usrfiles.com/ugd/b8c837_b935ffb06d364bbbab26a4ffbc5f59e0.pdf
    • https://static.usrfiles.com/ugd/0cd019_d4e1d6e019d742538f6379c75acce9d6.pdf
    • https://static.usrfiles.com/ugd/b8c837_fdfa90182a5d4bc28e25f13ed5d7ec77.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/

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00004538.bin
cecd9fd9ff4a68c0da46277d47f8b11e4b7c7dbd1aa3475253631f4133e4ee74
pdf-font-stream PDF embedded font (sfnt) at offset 0x4538 4924 bytes
font_01_sfnt_off000055e9.bin
8ab923703a6cb8420f8fca7bd3ad5728ba4bd58dd88d5cf9a7680080d3c28edf
pdf-font-stream PDF embedded font (sfnt) at offset 0x55E9 1908 bytes
font_02_sfnt_off00005f39.bin
a47e42d9a44e454cc83e7d2d6e4420b8d8cec2953bead63f02795e1395c08046
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F39 12496 bytes