Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8f4007daeb40ba4…

MALICIOUS

PDF

44.0 KB Created: 2020-09-10 21:33:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2e4b1269a8de25cba279b3969e00795f SHA-1: 43c8fd2c74605bfc57bdcdb86d286c8b1729a554 SHA-256: b8f4007daeb40ba4a9e96b6889eca490f8eb731730dae44260eb93ce80193277
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, which points to a URL designed to appear as a 'daily cash book format in excel'. This redirector leads to a large farm of SEO-optimized PDF links, predominantly hosted on static.usrfiles.com. The ML classifier also strongly indicated maliciousness. The primary attack vector appears to be luring users through deceptive content to a network of linked PDFs.

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.me/wix?keyword=daily+cash+book+format+in+excel
    • https://static.usrfiles.com/ugd/e66789_6f5d29df379a4f23935ff8bb15316d72.pdf
    • https://static.usrfiles.com/ugd/d55797_06bbed4581ff40cf8e5e5bad4e5273bb.pdf
    • https://static.usrfiles.com/ugd/078c79_575cb47dad1b40ad97d3729606d2e8ae.pdf
    • https://static.usrfiles.com/ugd/e02969_c0f4e5e148a740489d1d9c685620a782.pdf
    • https://static.usrfiles.com/ugd/6d59ab_2238723523104c7cb56321c7ef1dca58.pdf
    • https://cdn.shopify.com/s/files/1/0438/4771/2928/files/new_year_s_resolution_list_template_2019.pdf
    • https://cdn.shopify.com/s/files/1/0458/5973/3657/files/98824140331.pdf
    • https://cdn.shopify.com/s/files/1/0434/6766/9654/files/tetudedazipojanedi.pdf
    • https://cdn.shopify.com/s/files/1/0430/3293/6605/files/bahubali_movie_2017.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/jisabisagubimebusogapasof.pdf
    • https://static.usrfiles.com/ugd/7c41c1_e21dc04053434048ae3c08118e7bb957.pdf
    • https://static.usrfiles.com/ugd/f6336d_0039167e027141dab7ac08b63a451c5d.pdf
    • https://static.usrfiles.com/ugd/20d83a_d352079674614a2199d753c68b413037.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006ea1.bin
13086ef73ac62c7752382e3b6460c8d5e6cdb4531d4157d3399a71af875996ac
pdf-font-stream PDF embedded font (sfnt) at offset 0x6EA1 5496 bytes
font_01_sfnt_off00008139.bin
e7873beafb6b552e5f2e0635428d8fc030c90fc605e93249ce899678459dee41
pdf-font-stream PDF embedded font (sfnt) at offset 0x8139 9964 bytes