Malicious PDF — malware analysis report

Static analysis result for SHA-256 436a19e92e8fdcbd…

MALICIOUS

PDF

34.5 KB Created: 2020-08-29 09:04:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1748ca82721143beba0d4669648e3078 SHA-1: eefac246287315a2b8a75f22c011a42f35775a75 SHA-256: 436a19e92e8fdcbdc6bf35c83382e6a39b7bc8a5ad479f857a217e85cf979339
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains a URL that aligns with the redirector finding. The presence of numerous external PDF links, many hosted on static.usrfiles.com, suggests a link farm or SEO poisoning attempt to lure users to malicious content. The primary malicious IOC is the redirector URL.

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.cc/wix?keyword=bukhari+sharif+in+roman+urdu+pdf
    • https://static.usrfiles.com/ugd/b8c837_c94960b30676450a965010eded3d1249.pdf
    • https://static.usrfiles.com/ugd/b8c837_57c7de3b0d364c1fbf8deb0b00ac6e9d.pdf
    • https://static.usrfiles.com/ugd/b8c837_85462f0433d7413e9710f054460c3c46.pdf
    • https://static.usrfiles.com/ugd/b8c837_869ac493c09145dba22f0521491ed8c5.pdf
    • https://cdn.shopify.com/s/files/1/0432/8371/0117/files/82415691086.pdf
    • https://cdn.shopify.com/s/files/1/0437/4547/6762/files/chapter_7_maths_class_12_ncert_solutions.pdf
    • https://cdn.shopify.com/s/files/1/0429/8201/5135/files/54586105186.pdf
    • https://cdn.shopify.com/s/files/1/0437/4469/0337/files/autocad_2007_64_bit_free_utorrent.pdf
    • https://cdn.shopify.com/s/files/1/0437/4292/0869/files/nazusadinemenodu.pdf
    • https://static.usrfiles.com/ugd/b8c837_cebfd4218f284c44a4ef5ce093e729b0.pdf
    • https://static.usrfiles.com/ugd/b8c837_f649aabc47ad4a2eb5f785af23953cab.pdf
    • https://static.usrfiles.com/ugd/b8c837_425172f5ef1142d281c972b79a3e1579.pdf
    • https://static.usrfiles.com/ugd/b8c837_33c74c94f37c4cddb48eb36e31851825.pdf
    • https://static.usrfiles.com/ugd/b8c837_5675f68aa448463e81aba911dfb00fe6.pdf
    • https://static.usrfiles.com/ugd/b8c837_aa0ba7b175c2460bb63e320da8ee3f53.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_off00004936.bin
f1baf0b90ddd76b03db551d57b819fdb515cde54533b54c73f4db7e7d6f70646
pdf-font-stream PDF embedded font (sfnt) at offset 0x4936 5360 bytes
font_01_sfnt_off00005b4a.bin
b6a928e48c3e82c3dcbd34df000a370f66d9186f1291752b917537b1380eb5ab
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B4A 9956 bytes